w*. hi^' J' ^ .^^. Journal of tU Ropal microscopical Socletp CONTAINING ITS TRANSACTIONS AND PROCEEDINGS AND A SUMMARY OF CURRENT RESEARCHES RELATING TO (principally Invertebrata and Cryptogamia) EDITED BY CHARLES SINGER, M.A. M.D. F.R.C.P. WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND J. ARTHUR THOMSON, M.A. LL.D. A. N. DISNEY, M.A. B.Sc. Regius Professor of Natural History in the University of A berdeen FELLOWS OF THE SOCIETY, A. B. RENDLE, M.A. D.Sc. F.R.S. F.L.S. Keeper, Department of Botany, British Museum AND RALPH ST. JOHN BROOKS, M.A. M.D. D.P.H. D.T.M. & H. (Camb.) Minimis partibus, per totum Naturae campum, certitudo omnis innititur quas qui fiigit pariter Naturam \\x^\\.—LinncBus. FOR THE YEAR 1919 TO BE OBTAINED AT THE SOCIETY'S ROOMS 20 HANOVER SQUARE, LONDON, W.i OF Messrs. WILLIAMS & NORGATE, 14 Henrietta Street, London, W.C 2 AND OF Messrs. DULAU & CO., Ltd., 34 Margaret Street, London, W.i ^ v-H 1 ( ^ ) COUNCIL. Elected 21st January, 1920. P res lb cut. J. W. H. Eyre, M.D., M.S., F.R.S. Edin. ^ite-llrcstbcnts. Sir George Sims Woodhead, K.B.E., M.A., M.D., LL.D., etc. Frederic J. Cheshire. Percy E. Radley. Alfred N. Disney, M.A., B.Sc. treasurer. Cyril F. Hill. ^ccrctiirus. Joseph E. Barnard. David J. Scourfield, F.Z.S. #rbntaTi| glcmljcrs of Council. Maurice A. Ainslie, R.N, Herbert F. Angus. Maurice Blood, M.A., F.C.S. F. Martin Duncan, F.R.P.S. Arthur Earl and. Sir Robert Hadfield, Bart., D.Sc, F.R.S. T. H. Hiscott. James A. Murray, M.D. Julius Rheinberg. E. J. Sheppard. Charles Singer, M.A., M.D. Joseph Wilson. LIBRARIAN. F. Martin Duncan, F.R.P.S. EDITOR AND CURATOR OF INSTRUMENTS. Charles Singer, M.A., M.D. CURATOR OF SLIDES. E. J. Sheppard. CURATOR OF METALLURGICAL SPECIMENS. F. Ian G. Rawlins. a 2 * * HIS MAJESTY THE KING. ||ast-||rtsibcitis. ^^ *^ Elected *SiR EiCHARD Owen, K.C.B. D.C.L. M.D. LL.D. F.R.S. 1840-1 *J0HN LiNDLEY, Ph.D. F.R.S -. 1842-3 *Thomas Bell, F.R.S 1844-5 * James Scott Boweebank, LL.D. F.R.S 1846-7 *(Ieorge Busk, F.R.S 1848-9 *Arthur Farre, M.D. F.R S 1850-1 *George Jackson, M.R.C.S 1852-a *WiLLiAM Benjamin Carpenter, C.B. M.D. LL.D. F.R.S. 1854-5 •George Shadbolt 1856-7 *Edwin Lankester, M.D. LL.D. F.R.S 1858-9 John Thomas Quekett, F.R.S 1860 *Robert James Farrants, F.R.CS 1861-2 *Charles Brooke, M.A. F.R.S 1863-4 *James Glaisher, F.R.S '. 1865-6-7-8 *Rev. Joseph Bancroft Reade, M.A. F.R.S 1869-70 *William Kitchen Parker, F.R.S 1871-2 Charles Brooke, M.A. F.R.S 1873-4 *Henry Clifton Sorby, LL.D. F.R.S 1875-6-7 *Henry James Slack, F.G.S 1878 *LiONEL S. Beale, M.B. F.R.C.P. F.R.S 1879-80 *Peter Martin Duncan, M.B. F.R.S 1881-2-3 *Rev. William Hy. Dallinger, M.A. LL.D. F.R.S. 1884-5-6-7 *Charles Thos. Hudson, M.A. LL.D. (Cantab.), F.R.S. 1888-9-90 *Robert Braithwaite, M.D. M.R.C.S 1891-2 Albert D. Michael, F.L.S 1893-4-5-6 Edward Milles Nelson 1897-8-9 William Carruthers, F.R.S. F.L.S. F.G.S 1900-1 Henry Woodward, LL.D. F.R.S. F.G.S. F.Z.S 1902-3 Dukinfield Hy. Scott, M.A. Ph.D. LL.D. F.R.S. F.L.S. 1904-5-6 *The Right Hon. Lord Avebury, P.C. D.C.L. LL.D. F.R.S., etc 1907-8 Sir Edwin Ray Lankester, K.C.B. M.A. LL.D. F.R.S. F.L.S. F.Z.S ". 1909 J. Arthur Thomson, M.A. F.R.S.E 1910-11 *Henry George Plimmer, F.R.S., F.L.S., F.Z.S., etc 1911-12 Sir G. Sims Woodhead, K.B.E. M.A. M.D. LL.D. F.R.S.E., etc 1913-15 Edward Heron- Allen, F.R.S. F.L.S. F.G.S., etc 1916-17 Joseph E.Barnard ,. 1918-19 * Deceased. CONTENTS. TRANSACTIONS OF THE SOCIETY. I.— Presidential Address, 1917-18 : The Limitations of Microscopy. By Joseph E. Barnard, P.R.M.S. (One figure) .. 1 II. — Eye-pieces with Adjustable Compensation. By H. Hartridge, M.A., M.D., F.R.M.S., Fellow of King's College, Cambs. (One diagram) 15 III. — The Identification of Intracellular Structures. By J. Bronte Gatenby, Senior Demy, Magdalen College, Oxford, Lecturer in Cytology, Uni- versity College, London. (With fourteen text-figures) 93 IV.— A Method of Adjusting Tube Lengtli. By H. Hartridge, M.A., M.D., F.R. M.S., Fellow of King's College, Cambs. (One diagram) .. .. 119 v.— A Standard Microscope. By Lieut.-Col. J. Clibborn, CLE., B.A., F.R.M.S. 125 VI. — Tropical Diseases due to IVIicroscopic Organisms in the Balkanic Zone. By Aldo Castellani, M.D., M.R.C.P., Lieut.-Colonel Italian Medical Service (Naval Branch), Member of Permanent Committee, Inter-Allied Sanitary Commission. (One plate) 209 VIL— The Isolation of the Single Bacterial Cell. By Nathan IMutch, M.A., M.D. M.R.C.S. (From the Bacteriological Laboratory, Guy's Hospital.) (One text-figure) 221 VIII. — On the Chemistry of Dendritic Growths in Paper. By James Strachan, F.R.M.S * 225' IX.— On FolUcuUna boltoni (S. Kent). By E. Penard, Sc.D. (Two plates) . . 305 X. — Note on Cajal's Formalin-Silver Nitrate Impregnation Method for the Golgi Apparatus. By H. M. Carleton, B.A., Demonstrator in Histology, and Christopher Welch Scliolar, University of Oxford. (From the Department of Physiology.) (With three text-figures) 321 OBITUARY. H.J.Grayson. By W. M. Bale 20 ,' ^'^/J V] CONTENTS. r SUMMARY OF CURRENT RESEARCHES. ZOOLOGY. VERT;EBRATA. a. Embryolog-y, Evolution, Heredity, Reproduction, and Allied Subjects. PAGE Deips, Della — Ovary of SpermopMle 23 EiDDLB, Oscar — Identical Female 2 wins in Pigeons from Ova of High Storage Metabolism .. ' 23 „ „ & J. Arthur Harris — Blood-fat and Egg-production in Fowls . . 24 „ „ & Carl E. Anderson — Effects of Quinine on Production of Yolk and Albumen 24 Long, J. A. — CEstrous Cycle in Bats 24 PoTNTER, C. W. M. — Wound Healing in Early Embryo of Chick 25 EiDDLE, Oscar, & Victor K. La Mer — Post-mortem Melanin Formation in, Eyes of White Ring Doves 25 Danforth, C. H. — Brachydactijly in Fowl 25 Badertscher, J. A. — TJltimobranchial Bodies in Pig 26 Atwell, Wayne J., & Ida SiTLER — Development of Hypophysis 26 Baumgartner, E. A. — Development of Hypophysis of Reptiles 26 „ „ — Development of Hypophysis in. Dogfish 27 ASGhv:,^. J.— Development of Wolffian Body of Pig 27 Terry, K. J. — Development of Cat's Skull 27 Alsop, Florence M. — Influence of Abnormal Temperature on Developing Nervous System of Chick 27 Hartman, Carl — Development of Opossum 28 Reed, H. D. — Fenestral Ear Plate in Caudate Amphibia 28 Thuringer, J. M. — Dicephalic Pig 28 PoHLMAN, A. G. — Double Ureters in Pig and Man '28 Bv3AJiD,E.— Split Fore-brain in Sheep Embryo 28 Streeter, Gr. L. — Formation of Filum terminale 29 King, Helen Dean — Inbreeding and Sex-Ratio in Albino Rats 127 „ „ Inbreeding and Body Weight in Albino Rats 128 ., „ Inbreeding and Fertility in Albino Bats 128 Hatai, S. — Feeding Sudan to Young Albino Bats 128 KiRKHAM, W. B. — Suckling and Bate of Embryonic Development in Mice .. .. 128 Stockard, Charles R., & George N. Papanicolaou — Effect of Alcohol on Guinea- pigs ■ 128 Costa, A. Celestino da — Amnion-Formation in a Bat 129 „ ., Amnion Formation in Mammals 129 GuYER, M. F., & E. A. SmiH— Effect of Cytolysins on Embryos 129 Kollman, Max — Female Reproductive System in some Falcons , 130 'NEWMAi'i,H.. R.— Hybrids between Fundulus and Mackerel 130 Delage, Yves — HAnn^e Biologique 229 SvfiiiGhE,yil.'W.—Eff'ects of Iodine on Tadpoles .. .. ' 229 „ „ Influence of Iodine on Thyroid Gland of Tadpoles .. .. .. 229 EwART, J. CossAR — Sheep Crosses and New Varieties of Wool 230 CONTENTS. Vll PAGE Sumner, F. B. — Siiperfoetation in Mice 230 KiKKHAM, W. B. — Fate of Homozygous Yelloio 31 ice 231 Stark, Mary B. — Bereditary Tumour 231 Schmidt, W. J. — Neural Plateg af Chelonian Carapace 231 GhASKB., O. C— Neural Folds 232 UAKSo^,F.B.—CoracoidofPig 232 Morrill, C. V. — Symmetry Reversal and Mirror-imaging in Monstrous Trout . . 232 Atterbuky, Ruth Rand — Pharyngeal Tonsil and Bursa in Calf 232 Moore, Carl R. — Influence of Gonads in White Rats 233 Danforth, C. H. — Possihilily of Differential Selection of Germ-cells in Fowl .. .. 283 GooDALE, H. D. — Interstitial Cells in Gonads of Fowl 233 Allen, Ezra — Diet and Testicular Degeneration in Rat 234 Thomson, Arthur — Maturation of Human Ovum 329 Streeter, George L. — Formation of Single-ovum, Twins 329 Danforth, C H. — Selection among Germ-cells 330 GooDALE, H. D., & Grace Macmullen — Winter Egg-production in Poultry .. 330 Carazzi, D. — Development of Guinea-Pig (1 &g.) 330 Hanson, Frank Blair — Development of Pig's Siermim 331 Goodrich, Edwin S. — Development of Pericardio-peritonenl Canals in Selachians 331 Cull, S. T. Wallis — Spina bifida in very early Human Emhrijo 332 HosKiNS, E. R., & M. M. — Influence of Thyroid on Growth and Development of Amphibia 332 King, Helen Dean — Inbreeding-effects in Albino Rats 332 Stewart, Chester A. — Underfeeding Rats 333 Moore, Carl R. — Gonads as Controllers of Characteristics 333 LiPSCHi'TZ, A. — Sex-characters and Sex-glands 333 Murray, John G., Jun. — Relation of Ovary to Causation of Sep .. 333 Champy, Ch., & P. Colle — Correlation between Pigeon s Crop and Gonads .. .. 334 b. Histologry. Clark, Eleanor Linton, & Eliot H. Clark — Vital Staining of Tadpole's Tail 29 Jordan, H. E. — Histogenesis of Blood-platelets in Yolk-sac of Pig 29 McJunkin, F. A. — Origin of Phagocytic Mononuclear Cells 29 Scammon, R. E. — Structure of Corpus adiposum bnccx 30 Holmgren, Nils — Epiphysis of Dogfish 30 „ — Parietal Organs of Frog 30 ,. „ — Epiphysis Nerves in Sprat and Herring 31 Sumner, F. B., & H. H. Collins — Autotomy in Pocket Mice .. 31 Allen, Bennett M. — Experiments on Tadpoles 31 „ „ — Endocrine Glands of Frog and Toad 31 Larson, Mary Elizabeth — Endocrine Glands of Toad 31 Riddle, Oscar — Hereditary Ataxia in Pigeons .. 32 Koch, Mathilda L., & Oscar Riddle — Analysis of Ataxic Brains of Pigeons .. 32 Southwell, T., & B. Prashad — Tumours in Climbing Perch 32 Matsumoto, Shiniohi — Epithelial Movement in Tissue t^'ulture 130 „ — Cell Mo cements in Corneal Epithelium 131 Boktnowsky, Isaac — Minute Structure of Monkey's Pharynx 131 Retterer, Ed. — Structure and Origin of Dentary E7iamel 131 „ . „ —Cortex of Roots of Teeth 131 Redfield. Alfred C. — Melanophores of Horned Toad 132 MuRisiER, P. — Division of Melanophores of Trout 132 Vlll CONTENTS. PAGE Ba^liss.W.M.— Protoplasm and Cell Contents .. .. 234 » „ Nature and Permeability of the Cell Membrane 234 Legrasd, 'Lovis— Theory of Specifie Plasma 235 Lewis, Warren H. — Centriole and Centrosphere in Degenerating Fibroblasts .. 236 'Dersohav,M.\.— Passage of Solids from Nucleus to Cytoplasm 236 ScHREmER, K. E.— Minute Structure of Hagfish-skin 236 FoRTmR,PAVL— New Theory of Symhions 236 M.vmos,I. P.— Continuity of Cells and Amitotic Karyokinesis 237 Danchakofp, Vera— Properties of Mesenchyme 237 Beck, Clavvk S.— Distribution of Clasmatocytes 237 YAiiCE, PL. W. Structure of Clasmatocytes 237 NicHOLLS, George E.—i?emwe)-'s i^/6re 238 FhATBER, Mary TfRVSiLhA— Blood Supply of Areas of Langerhans 238 JoRDAti^H.E.— Intercalated Discs in Striped Muscle 238 MoOBiE, Roy L.— Antiquity of Bone Structure 238 A.SA\,TAKESBiRO—Mimite Structure of Membranous Labyrinth of Tadpoles .. .. 334 Lewis, Margaret Reed— Development 151 Wabren, Ernest — Pigment of Hydroids {2 &gs.) 152 „ „ — Structure of New South African Hijdroid 153 BiLLABD, Aemand— iVe?« »S|pecres o/ »S'e;0BIK, A. J. — List of Desmidiacese collected during the Summer of 1913 in the Government of Ufa 275 IjECnuERE, A. 'EcKLEY^Epiphyllic Ulothrix 275 Bristol, Muriel B. — Retention of Vitality by Algx from old Stored Soils .. .. 276 „ „ — Malay Form of Chlorococcum humicola (Ncig.) Rabenh. . . 276 Kufferath, H. — Contribution to the AJgal Flora of South Luxembourg 276 Flaytaib., G. I.— New and Rare Fresh-water Algse 277 CONTENTS. XIX PAGR Fritsch, F. E. — Freiih-water Algas of Africa 277 CoLLiNP, F. B. — Green Algx of North America: Second Supplement 277 „ „ • — Worhing Key to the Genera (f North American A]gx 277 Gardner, N. L. — New Facific Coast Marine Algas 278 Wolfe, J. J. — Alternation and Parthenogenesis in Padina 278 Cleland. Ralph E. — Cijtology and Life-histori/ of Nemalion multifidum Ag. .. 278 Cotton, A. D. — Distribution of certain British At gx 279 „ „ — Japanese Seaweed, Tosuha Nor i 280 Lucas, A. H. S. — Notes on Australian Marine Algx 280 Kylin, H., & C. Skottsberg — Sub-Antarctic and Antarctic Marine Algse. II. : Rhodoph>jceiB 280 Howe, Marshall A. — Calcareous Algxfrom Murray Island, Australia, and Cocas- Keeling Islands 280 Church, A. II. — Plankton-phase and PlanJcton-rate 375 Schroder, B. — Melosir a Roesearia Babenh., a Luminous Diatom 375 ScHUSSNiG, B. — Bemarhs on certain Adriatic Plankton BaciUarix 375 Quelle — Bemarhs on the Bacillariaceai of the Numhurg Stream 375 Lacsny, J. L. — Bacillariacefe of the Streams near Nagyvdrad 376 Petersen, J. B. — Studies of Danish Aero phihus Algse 376 ScHUSSNiG, B. — On some New and Bare Chlorophycese of the Adriatic 376 C\nTEn,T^Ehi,iE — Cytology of the Cladophoraceie 377 Bullock-Webster, G. R. — New Mtella .. 377 Groves, J., & G. R. Bullock-Webster — Chara fragilis and C. delicatula .. .. 377 Groves, J. — Notes on Lyclmothamnus 377 Howe, M. A. — On some Fossil and Becent Litlwthamniex of the Panama Canal Zone 378 Church, A. H. — Historical Beview of the Florid ex 378 Grunow, A. — Additions to our Knoioledge of Sargasstim 378 Church, A. H. — Phasophycean Zo'id 378 „ — Historical Bevieio of the Phxophycese 379 Fungi. Eriksson, Jakob — Study of Phytophthora infestans 62 KusANO, S. — Life-History and Cytology of Vlpidium 62 Rhoads, Arthur S. — Daldinia rernicosa 62 DuRAND, E. J. — Peziza proteana rar. sparassoides in America 62 Grove, W. B. — British Species of Melanconinm 62 „ — New or Noteicor thy Fungi 63 Stone, R. E. — Licubation Period of Cronartium ribU-oJa on the Wliite Pine . . . . 63 Cruchet, Paul — Contribution to the Sttidy of Uredinese *j3 Arthii;, J. C, & G. R. BiSBT — Rusts of North America 63 DoSDALL, Louise — Overwintering of ^Fciospores of Cronartium ribicola 63 RuoADES, Arthur S., & others — Host Belationship of the North American Rusts, other than Gymnosporangium. ichich attach Conifers 63 Weir, J. R., & E. E. Hubert — Melampsora Cultures 64 Jackson, H. S. — Puccinia on Carduarean 64 Arthur. J. C. — Study of the Genus Kuehneola 64 Dodge, B. D. — Study of Gymnosporangium 64 Elliott, J. S. Batliss — Hyphomyretes 64 Smith, A. LoRRAiN — Hyphomyretes and the Rotting of Timber 64 Rathburn, Annie E. — Fungus Flora of Pine Seed-beds 65 b 2 XX CONTENTS. PAGE Brieblt, W. B. — Polymorphism of Botrytiscinerea 65 Cleland, J. Burton, & Edwin Cheel — Notes on Australian Fungi N. IV. .. .. 65 Peaeson, A. A. — Two-spored Basidia 65 Rea, Carleton — British Mycology 65 Faull, J. H. — Fomes officinalis, a Timber-destroying Fungus 65 HoENE, A. S. — Fungi on Aleurodes raporarium 66 Gfissow, H. T. — Fmpusa Musex on Musca domestira 66 Brieeley, W. B. — Cell-regeneration in Botrytis cinerea 66 MuREiLL, W. A.- — Illustrations of Fungi 66 Harper, Edwaed T. — Notes on Hypholoma 66 Elliott, J. A. — Coriolus proliflcans and C. versicolor on Peach Trees 66 Weiss, J. E. — Effect of Weather on the Attacks of Parasitic Fungi 66 Lauritzee, J. L. — Relation of Temperature and Humidity to Infection by certain Fungi . ■ . . 67 Mitea, S. K. — Effect of Salts on the Growth of Wine-yeast 67 Barrus, Moetier F. — Varietal Susceptibility of Beans to Strains of Colletotrichum Lindemuthianum 67 Wakefield, E. M. — Biology of Sand-dune Fungi 67 ., „ & A. A. Pearson — Fungus from Weybridge 67 ,, „ — Fungi Exotici : xxiv 68 Faieman, Ch. E. — New or Noteivorthy Fungi from New Mexico 68 Tanaka, Tyozaboro — New Japanese Fungi 68 Pegler, Alice, & I.B.Pole Evans — Cape Fungi 68 Smith, A. Lorrain, & others — New or Rare British Fungi 68 Elliott, J. S. Bayliss — Neio Species of ^^ Fungi imperfecta " 68 Cruchet, Paul — Fungi on Bromus 68 Burkholder, Walter H. — Production of an Anthracnose-resi slant White Marrow- bean 69 Smith, A. Lorrain — Relation of Fungi to other Organisms 69 ^^'lhTsnlB.E, S. F.— Infection and Immunity .. .. 69 AsAi, ToiCHi — New Tannery Fu7ujus 69 Williams, Maud — Absorption af Gold by Fungi 69 Fawcett, H. S. — Geographical Distribution of Citrus Diseases 69 ., — Relation of Temperature to Groicth of Fungi in Cultures .. .. 69 Butler, E. J. — Fungi and Disease in Plants 70 Hodgson, Robert W. — Sterigmatocystis Smut of Figs 70 Demandt, Ernst — Cacao Disease 70 Zinssmeister, C. L. — Root-rots of Ginseng 70 Brooks, F. T., & A. Sharples — Pinlc Disease of Plantation Rubber 70 Robinson, W. — ''.Black Neck" or Wilt Disease of Asters 71 Smolak, T. — Silver-leaf Disease 71 RosENBAUM, J. — Tomato-fruit Rots „. .. . .. 71 Shapovalov, M. — Some Potential Parasites of the Potato Tuber 71 Wakefield, E. M. — Diseases of Yams 71 Henderson, M. P. — Disease of Cabbage 72 Sharples, A. — Rubber Disease 72 Wortley, E. J.— Potato Lea/- roZi 72 Cotton, A. D. — Diseases of Parsnip 72 Alcock, N, L. — Rose-blotch Fungus ' 72 Coons, G. H. — Treatment of Scab in Potato Tubers 72 WoEMALD, H. — Blossom Wilt and Canker of Apple-trees 73 ^^ —'■' Wither Tip" of Plum-trees 73 CONTENTS. XXI PAGE Belgrave, W. N. C. — Disease due to Gytospora 73 Van der Bijl, P. A. — Diseases of Carnations 73 Stevens, Neil E., & K. B. Wilcox— Wi/zo/»us i?o< o/iSira^cbemeg 175 VuiLLBMiN, Paul — Notes on Morlierella 175 Eriksson, Jakob— Origin and Development of the Potato Disease, Phyfophthora infestans l'** VuiLLEMiN, P. — New Brown Aspergillus, Eurotium verruculo3um 175 YmcETHS, F.— Character of Taxonomin Value in XyJariaceiB 176 „ — Organogenic Researches on Hi/pocreales 176 GviLhERiiOT!iD, A.— Zygosacchiromyces Nadsofiii sp.n 176 DcFOUR, Leon — Vegetation of Plicaria leiocarpa 176 Chenantais, J. — Three Di^comycetes 176 Palm, Bj. — Scandinavian Taphrina Species 17/ BuREN, G. V. — Contribution to the Knowledge of the Mycelium of the Genus Volkartia 1 77 Darnell-Smith, G. P. — An Account of some Observations upon the Life-history of Phoma citricarpa McAlp 177 Anderson, P. J. — Index to American Species of Phyllosti eta 177 Davis, J. J. — North American Ascocliytx 178 CoLTON, A. D. — Onion Smut 178 Elliott, John A. — Smuton Iresine 178 Fischer, Ed. — Experiments with Uredinex 178 Bethel, Ellsworth — Pucrinia suhnitens and its JEcial Hosts 178 Arthur, J. C. — New Species of Uredinex 179 Leach, Julian G. — Parasitism of Puecinia .. .. 179 Wilson, Malcolm — British Rust Eungi 179 Fischer, Ed. — Mycological Contributions 179 Dreschler, Charles — Morphology of the Genus Actinomyces 180 Lange, Jakob E. — Studies in the Agari'-s of Denmark 180 Darnell-Smith, G. — Occurrence of an Inverted Hymenium in Agaricus campestris 180 Cleland, J. Burton, & E. Cheel — Notes on Australian Fungi. No. 1 V. Polyporus, Fames, and Hexagona 181 Petch, T. — Ceylon Lentini 181 ., — Ceylon Polypori 181 Patouillard, N. — Conidial Forms of Basidiomycetes 181 Lloyd, C. G. — Mycological Notes 181 Bataille, F. — French Mycology 181 Moiieau, Fernand — Technical Microscopic Methods for the Study of Fungi .. .. 18'2 Weir. James R. — Introduction of Wood-destroying Fungi 182 Graff, Paul W. — Philippine Basidiomycetes 182 Tanaka, Tyozaburo — New Japanese Fungi 182 Politis, Ioannes — Greek Mycology 182 Kauffman, C. H. — Michigan Fungi 182 'PAVij,'D.—Clathrus cancellatus in Scotland 182 JuiLLARD, G.. & H. Pierre— Frenc/t Mj/coZo^i/ 183 Petch, T. — Additions to Ceylon Fungi 183 „ — Revisions of Ceylon Fungi (Parti IV. and V.) 183 MoREAU, Fernand — Discoloration of Paper Pulp due to Fungi 183 DuFRENOY, J. — Ecological Conditions in the Development of Parasitic Fungi : Study of Geographical Botany 183 Lloyd, C. G. — Xylaria Notes 184 Leonie, IMichael — Sporadic Appearance of Non-edible Mushrooms in Cultivated Mushroom Beds 181 XXll CONTENTS, PAGE Shear, C. L., & others — Endothia parasitica and Related Species ]84 TuRCONi, Malusio, & LuiGi Maffei — Parasitic Microfungi 184 Dt'FRENOY, J. — Parasite of Arbutus Unedo 185 Chifflot, J. — Ergots of Bye 071 Wheat 185 BiJL, P. Van DEB — Cane- Leaf Spot 185 Briosi, Giovanni, & RuDOLFO Farnete — Disease of Chestnuts 185 Shear. C. L„ & others — Spoilage of Cranberries after Harvest 185 B,ATasBOTTOM, J. K.—Investigatio7is on the Narcissus Disease 185 Piper, C. v., & H. S. Cox — Rhijzoctonia on Lcvwus and Pastures 186 Brooks, F. T. — Silver-leaf in Fruit-trees 186 Bessey, Ernst A. — Undescribed Species of Ophiodothella on Ficus 186 Stevens, Frank Lincoln — Two Illinois Rhubarb Diseases 1S6 Davis, J J. — Notes on Parasitic Fmigi in Wisconsin 186 CcTRTis, K. M. — Contributions to the Life-histovij and Cytology of Synchytrium endobioticum 281 Burger, Owen F. — Sexuality in Cnnninghamiella 281 Tisj)A'L^,^.Yi..—Physoderma Disease of Corn 281 Stevens, T. L., & Noha Dalby — Some Phyllachoras from Porto Rico 281 Chenantais, J. E. — Study of Pyrenomijcetes 281 FiTZPATRiCK, A. M. — RostronitschJcia, a New Genus vf Pyrenomycetes 282 Rano'ievitch, N. — New Species of Rust, Puccini a Corteyi Ran 282 Orton, C. E. — Notes on Some Polemoniaceous Rusts 282 Garrett, A. O. — Smuts and Rusts of Utah 282 Cotton, A. D., & E. M. Wakefield — Revision Y^OP&is of Beceut Chemical and Metallurgical Literature 299 Andeuson, Robert J. — Metallograpluj of Aluminium Ingot 299 Phillips, Arthur, & George C. Gerner — Notes on the Influence (f Certain Variables associated loith the Anneal of Cold-worhed Alpha Brass .. .. 299 Heyn, E., & O.Bauer — Researches on Bearing Metals 299 Smith, P]unest A., & Harold Turner — The Properties of Standard or Sterling Silver, loith Notes on its Manufacture 299 Hatfield, W. H., & G. Ij. THiHKELL—iS'easoM Oracfen;/ .. 299 Hatfield, W. H. — Tlie Mechanical Properties of Steel, witli some Consideration on the Question of Brittleness 385 Whiteley, J. H., & K.Y.YiKhhmofiu— The Acid Hearth and Slag 385 Portevin, a. M., & M. Garvin — The Experimental Investigation of the Influence of the Rate of Cooling OH the Hardening of Carbon Steels 385 Taylor, G. — Some Points in the Manufacture of Files 385 Council Meetincjs are held on the third Wednesday, Meetings of the Biological Section on the first Wednesday in each month from October to June. Fellows intending to exhibit any Instruments or Objects, or to bring forward any Communications at the Ordinary Meetings, are requested to inform the Secretaries a week before the Meeting if possible. CONTENTS. XVll PAGE HiERONTMUS, G. — Co7itributions to a Knowledge of the Genus Pteris ■ 269 RiCHTER, Aladar — Ncw ScMzasa from Bomso (8. BalUeri) 269 Stokey, Alma G. — Apogamy in the Cyatheacea^- 371 OsBOKN, T. G. B. — Observations on the Tuber of Phylloglossum 371 Hill, J. Ben — Anatomy of Lycopodium reflexum 372 Steil, W. N. — Method of staining Antherozoid of Fern 372 &m,T.B..— Ferns of Soidh Africa 372 Bryophyta. GoEBEL, K. — Organography of Plants 57 Evans, Alexander W. — Air Cliamhe.rs of Grimaldi fragrans 58 DouiN, Ch. — Mixtures of Species among the Gephaloziellacese 58 Watson, W. — Sphagna, their Habiiats, Adaptations and Associates 59 Smith, Gilbert Morgan — Cell-Structure and Autospore Formation iu Tetraedron minimum 59 Toda, Y. — Studies on Schistostega osmundacea 59 Dixon, H. N. — Mosses Collected by the Srnithsoiiimi African Expedition 60 Haupt, Arthur W. — Morphological Study of Pcdlavirinia Lyellii 163 Evans, Alexander W. — Taxonomic Study of Dumortiera .. .. 163 „ ., — American Species of Marchantia 163 „ ., — Noteworthy Lejeunesi from Florida 161 ,. ., — Notes on. New England llepaticx 164 — Hepaticse of St. Croix, St. Jan, St. Thomas, and Tortola 164 Frye, T. C. — Illustrated Key to the Wedern Sphagnacex 164 Skene, ]M. — Acidity of Sphagnum and its Relation to Chalh and Mineral Salts .. 164 Koell, J. — Sphagna and Mosses of Thiiringen 164 AVaknstorf, C. — Vegetatire Increase of Ptergynandranijiliforme {Timm) Hedio. .. 165 Gyokffy, I. — Histology vf Ephemeropsis tjibodensis Gnebel 165 Brotherus, V. F. — Moseniella : a New Moss Genus from Bratil 165 Aenell, H. W., & C. Jensen — Bryum vermigerum 165 CoKER, Dorothy — Bevision of the North American Species of Encalypta 166 Herzog, T. — TiDO Cleistocarpie 3Iosses of the Bolitian High Cordilleras 166 MoLLER. H. — Moss Distribution in Sweden 166 Au^Khi^U.W.— Mosses of the'' Vega" E.vpeditioii 166 Dixon, H. N. — Uganda Mosses 167 FiEGHmG-EYi,K.— Mosses and Ferns from the Pacijic 167 Brotherus, V. F. — Contributions to the Moss-flora of the Argentine 167 Campbell, D. H. — Studies on some East Indian Hepaticse 270 Kashyap, S. R. — Androecium in Plagiochasma appendiculatum L. etL. and P. arti- rulatuni Kashyap 270 Schilberszky, K. — N ew Moss from the Pleistocene (f Kecskemet, Hungary .. .. 270 Williams, R. S. — Genus Desmatodon in North America 271 Brotherus, V. F., (fc W. Walter — Mosses of North Queensland .. .. .. .. 271 Moss Exchange Club .. .. , 271 Cbibbs, J. E. — Columella in Marchantia polytnorpha 372 VON Dankenschweil, H. W. — Contribution to the Anatomy of Mosses 373 Buoh, H. — Scapania curta and its Allies 374 Meylan, Ch. — Desmatodon Wilczekii 374 Wheldon, J. A. — Notes 07t Braithwaite's '' Sphagnacece Exsiccatse'' 374 1)1X01^,11. N.— Miscellanea Bryologica ."74 b XVIU CONTENTS. Thallopliyta. Algae. PAGE Hattoki, H. — Mlcrobiologlcul Researches on some Japanese Water-supplies .. .. 60 Nakano, H. — Besearrhes on the Development and Nutrition of some Chlorophyceas 61 Moore, G. T. — A Wood-penetrating Alga, Gomontia Hi. C— Disease due to Cytospora 73 Van der Bijl, P. A. — Diseases of Carnations 73 ^TEWEss, liiEi-LE., & U.B. ^WlLcox— Ehizupus Bot of Stratvberries 175 Vdillrmin, Paul — Notes on Mortierella 175 EiUKSSON, Jakob — Origin and Development of the Potato Disease, Phyfophthora infestans 175 VuiLLEMiN, P. — New Brown Aspergillus, Eurotium rerriKulosum 175 YiyiCEHis, F.— Character of Tazonomic Value in Xylariacese 176 „ — Organogenic Researches on Hi/poereales 176 GrUiLLERMOND, A. — Zygosaccharomyces Nadsunii sp. n 176 Dtjfouk, Leon — Vegetation of Plicaria leiocarpa 176 Chenantais, J. — Three Di^comycetes 176 Palm, Bj. — Scandinavian TaphHna Species 177 BuREN, Gr. V. — Contribution ti the Knowledge of the Mycelium of the Genus Volkartia 177 Darnell-Smith, G. P. — An Account of some Observations upon the Life-history of Phoma citricarpa McAlp 177 Anderson, P. J. — Index to American Species of Phyllosticta 177 Davis, J. J. — North American Ascochytx 178 Couaoii, A. D.— Onion Smut 178 Elliott, John A.— SmM< o?i /resi'ne 178 Fischer, Ed.— Experiments with Uredineas 178 Bethel, Ellsworth — Pucrinia suhnitens and its JEcial Hosts 178 AwTHmi, ,'i. C— New Species of Uredinem 179 Leach, Julian G. — Parasitism cf Puceinia 179 Wilson, Malcolm — British Rust Fungi 179 Fischer, Ed. — MycologicaJ Contributions 179 TiKESGHijER, Q,HKni.ES— Morphology of the Genus Actinomyces 180 La NGE, Jakob E. — Studies in the Agarics of Denmark 180 Darnell-Smith, G. — Occurrence of an Inverted Ilymenium in Agaricus campestris 180 Cleland, J. Burton, & E. Cheel — Notes on Australian Fungi. No. 1 V. Polyporus, Fames, and Hexagona 181 Fetch, T. — Ceylon Lentini 131 „ — Ceylon Poly pari 181 Patouillard, N. — Conidial Forms of Basidiomycetes 181 Lloyd, C. G. — Mijcological Notes 181 Bataille, F. — French Mycology 181 MoREAU, Fernand— ree/jmca? Microscopic Methods for the Study of Fungi .. .. 182 Weir, James R. — Introduction of Wood-destroying Fmigi 182 Graff, Paul W. — Philippine Basidiomycetes 182 Tanaka, Tyozaburo — }iew Japanese Fungi 182 Politis, Joannes — Greek Mycology 182 Kauffman, C. H. — Michigan Fwigi 182 Paul, D. — Clathrus cancellatus in Scotland 182 Juillard, G., & H.Pierre — French Mycology 183 Petch, T. — Additions to Ceylon Fungi 183 „ — Revisions oj Ceijl on Fungi (Parts IV. and V.) 183 MoREAU, Fernand — Discoloratiou of Paper Pulp due to Fungi 183 DuFRENOY, J. — Ecological Conditions in the Development of Parasitio Fungi : Study of Geographical Botany 183 Lloyd, C. G. — Xylaria Notes 184 Leonie, Michael — Sporadic Appearance of Non-edihle Mushrooms in Cultivated Mushroom Beds 184 XXU CONTENTS, PAGE Shear, C. L., & OTHERS — Endothia parasitica and Related Species ISi TuRCONi, Malusio, & LuiGi Maffei — Parasitic Microfungi 184 DuFRENOY, J. — Pa rasHe of Arbutus Unedo 185 Chifflot, J. — Ergots of Bye on Wheat 185 BijL, P. Van der — Cane- Leaf Spot - 185 Briosi, Giovanni, & Rudolfo Farnete — Disease of Chestnuts 185 Shear. C. L„ & others — Spoilage of Cranberries after Harvest 185 Ramsbottom, J. K. — Investigations on the Narcissus Disease 185 Piper, C. v., &■ H. S. Cox — Rhijzoctonia on Lawns and Pastures 186 Brooks, F. T. — Silver-leaf in Fruit-trees 186 Bessey, Ernst A. — Undescribed Species of Ophiodothella on Ficus 186 Stevens, Frank Lincoln — Two Illinois Rhubarb Diseases 186 Davis, J J. — Notes on Parasitic Fungi in Wisconsin 186 Curtis, K. M. — Contributions to the Life-history and Cytology of Synchytrium eiidobioticum 281 Burger, Owen F.— Sexuality in Cunninghamiella 281 TiSDAhK,W.Il.—Physoderma Disease of Corn 281 Stevens, T. L., & Noha Dalby — Some Fhijllachoras from Porto Rico 281 Chenantais, J. E. — Study of Pijrenomijcetes 281 Fitzpatrick, A. M. — RostronitschJcia, a New Genus of Pyrenomycetes 282 Kanoievitch, N. — New Species of Rust, Puccinia Corteyi Ran 282 Orton, C. R. — Notes on Some Polemoniaceous Rusts 282 Garrett, A. O. — Smuts and Rusts of Utah 282 Cotton, A. D., & E. M. Wakefield — Revision of the British Clavariae 282 MoDouGAL, W. B. — Development of Stropharia epimiicts 282 Atkinson, G. F. — Relationships within the Rhodosporcse 282 Burt, Edward Angus — Thelephoracem of North America 283 KoNRAD, P., & Rene Maire — Notes and Observations on Agarics 283 Walker, Leva B. — Development of Piuteus admirabiiis and Tuburia furfuracea . . 283 Merrill, E. D., & H. W. Wade — Validity of the name Discomyces for the Genus of Fungi rariously called Actinomyces, Streptothriz, and. Nocardia .. .. 283 Wakefield, E. M., & A. A. Pearson — Additional Rempinate Hymenomycetes from the Weybridge District 283 Fetch, T. — Further Notes on Coins Gardneri {Berh.) Fischer 284: BOYER, G. — Studies on the Biolc.gy and Culture of the Higher Fungi 284 Pethybridge, G. H. — Notes on some Saprophytic Species of Fungi associated with Diseased Potato Plants and Tubers 284 Wakefield. ]\r. — British Mycology : The Selby Foray 285 Duprenoy, J. — Ecological Diversity and Generic Coefficients 285 Lagarde, J. — Cave Fungi 285 Wakefield, E. M. — New British Fungi .. 286 Pearson, A. A. — A^ew71f?/cena.. .. .. 286 Smith, A. Lorrain — New or Rare Microfungi 286 Cotton, A. D. — Entomogenous F%iiigi New to Britain 286 Wager, Harold — Fluorescent Coloring Matter from Leptonia incana 286 Brierly, W. B. — Some Concepts in Mycology -. An Attempt at Synthesis 286 Bracket Fungi of Citrus Trees 287 Cotton, A. D. — Occurrence of Oah-mlldew on Beech in Britain 287 Reinking, Otto A. — Phytophthora Faberi 3Taubl. : The Came of Coconut Bud Rot in the Philippines • .. 287 WoRMALD, H. — '' Bro'wn-rot " Disease of Fruit-trees: with Special Reference to two Biologic Forms of Monilia cinerea 287 CONTENTS. XXIU PAGE Brooks, F. T. — Account of some Field Obtervations on the Development of Potato Blight 288 Dey, p. K. — Studies in the Phijsiology of Parasitism. V. Infection by Colleto- trivhum Lendemuthianum 288 Krakovek, J. — Disease of Red Clover 288 Haskell, Royal J. — Fusarium Wilt of Potato in the Hudson River Valley, New York '.. .. 288 B,EiNKisQ, Otto— Philippine Plant Diseases 280 Krakover, L. J. — Leaf-spot Disease of Red Clover caused by Macrosporium sar- cinxforme 289 'PETB.YBmT>Cx^,G.Yj.— Disease of Flax Seedlings 289 Recent Work at the Pathological Laboratory, Keio Gardens 290 Edgerton, C. W. — Neio Balansia on Cyperus 379 Stevens, F. L., & Nora Dalbey — Parasite of the Tree-fern (Cyathea) 379 FoEX, Etienne — Note on a Cordyceps 379 Atkinson, G. F. — Phylogeny and Relationship i n tlie Ascomycetes .. 379 Doran, Wm. D. — Minimum, Optimum, and Maximum Temperatures of Spore Germi- nation in some Uredinales 380 West, Erdman — Undescribed Timber Decay of Hemlock 380 Faull, J. H. — Pineapple Funtjus, or Enfant du Pin or Warubou 380 Murrill, W. A. — Some described Species of Poiia .. ■■ .. .. .. 380 Ovep.holts, L. D. — Some Colorado Fungi 380 Church, A. H. — Fungi as Members of the Subxrial Transmigration 380 Mayor, Eug. — Contribution to the Study of the Mycological Flora of the Chateau d' CEx Region 381 Ellis, David — Fossil Micro-organisms from the Jurassic and Cretaceous Rocks of Great Britain 381 VooEL, Irwin H. — Rose Graft Disease 381 Shapovalov, M. — Is the Common Potato Scab Controllable by a mere Rotation of Crops? 332 Fitzpatrick, H. M. — Publications of George Francis Atkinson .. '. 382 Brandes, E. yV.—Baiiana Wilt . . 382 Pethybridge, G. H. — Destructive Disease of Seedling Trees of Thuja gigantea . . 382 Lichens. Smith, A. LoRRAiN — Lichenology in Great Britain 73 „ „ —Monograph of British Lichens 73 Fink, Bruce — New Lichen Genus 74 "Watson, W. — Lichens of Sand-dunes 7-1 „ — Bryophytes and Lichens of Calcareous Soil ". . . 74 Paulson, R. — Notes on the Ecology of Lichens 74 Mayfield. A. — Lichens of a Boulder-clay Area 74 MoREAU, Fernand & Madame — Researches on Lichens of the Family Peltigeracese 290 Lynge, Bernt— i?raz/Z ParmeZ/iB 290 Riddle, Lincoln W. — American Lichens 290 MoREAU, F., & Madame — Biomorphogenesis in Lichens 290 Braun, Lucy E. — Vegetation of Conglomerate Rocks of the Cincinnati Region .. 291 Gall0e, O. — Studies of Lichen Struct^cre and Development 291 Magnusson, A. H. — Contribution to the Lichen Flora of the West Coast 383 „ „ — Concerning the Species of Broicn Parmelix and Hypcgymise, their Occurrence and Fertility, especially on the West Coast 383 XXIV CONTENTS. Mycetozoa. PACK Lister, G. — Shrewsbury Myceiozoa 75 „ — Haunts of the Mijceiozoa 75 „ — Mycetozoa in Britain 75 Ross, Joseph — Mycetozoa of Chingford District 75 Lister, Gl'LIelma — Mycetozoa found during the Selhy Foray 291 Beardslee. H. C. — Michigan Colleclion of Myxomycetes 291 Patouillakd, N. — Mijxomycete from Madagascar 291 Briosi, Giovanni — Study of Plasmodiophora Brassicx 292 MEYiiAN. Ch. — Notes on Species of Myxomycetes 383 Schizophy ta. Schizomycetes. Haughwont, Frank G. — Infections with Cocridium and Isonpora in Animals in the Philippine Islands, and their possible Cliniral Significance {F\gs. 1-5) .. .. 292 DoNCASTER, L. — Mutation in Bacteria 293 Reinking, Otto A. — Philippine Economic Plant Diseases 293 Cedercretjtz, Axel — All Dead Bacteria are not Ag-positice 293 Bullock, W. E., & W. Cramer — On a New factor in the Mechanism of Bacterial Infection 294 Mello, Froilano de, & J. F. 8t. Antonio Fernandes — Revision des Champignons A'ppartcnant au Genre Ndcardia 294 MICKOSCOPY. A. Instruments, Accessories, etc. (3) Illuminating' and other Apparatus. Strutt, R. J. — The Light scattered by Gases ■ its Polarization and Intensity .. 76 Lambp:rt & OTHERS — Opacimeter for Standardizing Bacterial Emulsions (Fig.) .. 295 (5") Microscopical Optics and Manipulation. National Physical Laboratort — Report for the Year 1917 -^9] S 77 B. Technique. (3) Cutting, includiner Embedding and Microtomes. Goo-DSJ-EEDjT.U.— Modification of Hand Microtome (^l ^g.) .. 78 * (4) Staining and Injecting:. Arnaud, Roger — Note on the New Rapid Staining of Blood and Parasites in Films 297 CONTENTS. XXV C6) Miscellaneous. ^ PAGE Tsnjr, HiKOSHi, & Karagoro Tachibana — Antiseptic Treatment of Wounds .. .. 297 Hatschek, Emil — .1 Study of the Forms >sumed by Drops and Vortices of a Gelatinizing Liquid in Various Coagulating Solutions 88-t McLennan, J. C, & E. J. Laxg— ^h Investigation of Extreme Ultra-violet Spectra, with a Vacuum Grating Spectograph 38 i GEOLOGY. JIanesse, E. — Rocks of Italian Somaliland 385 Stopes, M. C. — On the Four Visible Inrjredients in Banded Bituminous Coal : Studies in the Composition of Coal, No. 1 , .. ., 385 Smith, B. —The Chellaston Gypsum Breccia in relation to the Gypsum-Anhydride Deposits of Britain 385 Lang, W. D. — The Eelestomnise : a Sub-family of Cretaceous Cribimorph I'olyzoa 385 METALLOGRAPHY, Etc. Krynitzky, A. I. — Decomposition of Metals 81 Smout, J. — Etching Media commonly ifsed in Non-ferrous Melallogruphy .. .. 81 Hanson. D. — Rapid Re-crydallizaiion in Deformed Non-ferrous Metals 81 AsBER&O's, Robert J.— The Metallography of Aluminium 81 Hanson, D., & S. L. Archbutt— 27ie Micrography of Alumininm and its Alloys.. 81 Johnson, F. — .4 Feio of some of the Mechanical Properties of the Alloys of Copper and Zinc 81 EosENHAiN, W. — The Properties of some Copper Alloys 81 liAVSEN,F. F.,& O. A. KiiiGB.T~-Eff'ect of ITeat Treatment on Bronze 81 Howe, & others— FZoA:es in Alloy Steel 82 Akchee, E. S. — Grain Limits in Heat-treated Alloy Steels 82 CoMSTOCK, G. F. — Neio Light or. Transverse Fissures 82 Hott. Samuel L. — Static, Dynamic and Notch Toughness 82 Grotts, F. — The Metallography of Heat Treatment of Metals used in Aeroplane Construction II. .. , 82 jMillek, S. W. — Fusion Welding Applied to Drop Forging^ 290 Hanson, D., & J. E. Hurst — Improved Case-hardening Process 209 'R'aTTERVfORTii.,G.Y., & K.F.Beiaas— Characterises (f Rifle-barrel Steel .. .. 299 '^Ysovsis of Recent Chemiccd and Metallurgical Literature 299 Andeuson, Robert J. — Metcdlographij of Aluminium Ingot 299 Phillips, Arthur, & George C. Gerner— iVo 1919 Tomlinson, Thomas Willis Brown. High-street, Berkhamsted. 1919 Toplev, William Whiteman Carlton, M.B., F.R.C.P., M.R.C.S,etc. The Institute of Pathology, Charing Cross Hospital Medical School, Chandos-street, \V.C.2 1918 Triggs, Edward E. 39, Scarborouglt-str< et. West Hartlepnol, Durham. 1917 Tripp, Charles Llewellyn IT., M.K.C.8., L.R.C.P. The Chestnuts, Staj)legrove, Taunton, OKDINARY FELLOWS. 23 Elected. 1915 Tutt, Captain John Francis Donald, M.K.C.V.S., F.Z.S. 1, St. Cross-road, Winchester. 1882 Tuttle, Albert Henry, M.Sc. University of Virginia, Charlottesville, Va., U.S.A. 1913 Verrall, Frederick H., B.A., LL.B. The Hollies, Worthimj, Sussex. 1909 Walter, Rev. Frederick William. The Grange, Worstead, Norfolk. IS'^^ ^Walters, James Hopkins, M.E.C.S. 15, Friar-street, Beading. 1869 Ward, Frederic Henry, M.E.C.S. 52, Lancaster-road, West Norwood, S.E.27 1885 Warner, Edmond. Southend House, Eltham, S.B. 1911 Warrington, Capt. A. F. G., F.R.G.S. CrooMam, 11, Khartoum-road, Highjield, Southampton. 1883 Waters, Arthur William, F.L.S., F.G.S. Alderley, McKinley-road, Bournemouth. 1919 Watte, George William, L.D.S.Eng. 103, Haverstock-hill, N.W.d 1912 Webb, Wilfred Mark, F.L.S. The Hermitage, Hanwell, W. 1897 Webster, William Thomas. 252, Caledonian-road, N.l 1885 *Western, Edward Young. 27, Pemhridge-square, Notting-hill-gaie, W.3 1895 White, Charles Powell, M.D., F.R.C.S., L.R.C.P., Pathological Department, Victoria University, Manchester. 1, Albemarle-road, Withington, Manchester. 1886 *Whitehead, Ralph Eadcliffe. Woodstock, Ulster C, N.T., U.S.A. 1898 Whittaker, Oscar, F.E.S. " Ormidale," Ashlands, Ashton-upon-Merscy, Cheshire. 1915 Whitteron, Frederick. " Dysart," Maude-street, Geclong, Victoria, Australia. 1913 Wigan, Basil P., F.C.S. Bhondda-valley Breweries Co., Treherhcrt, S. Wales. 1910 Wigginton, Panks James. 3, Park-crescent, Brighton. 1910 Wilding, Percy P. Hurstwood, Chapel-lane, New Longton, near Preslony Lanes. 1916 Wilkin, Corporal Arthur P., F.B.H.S., F.Z.S., F.R.B.S. 22, Buruaby -gardens, Chisivick, W. 24 ROYAL MICROSCOPICAL SOCIETY. Elected. 1908 Wilson, Joseph. The Hawthorns, 3, West-park-road, Keiv-gardens, S. W. 1911 Wilton, Edmund Wade, A.I.S.E., F.S.A. Planet Works, Bramley, Leeds, and Cliff Vieio, Pollard- lane, Newlay, near Leeds. 1909 Winton, Francis Langridge, M.A, The Brewery, Chatteris, Camhs., and 23, Bateman-street, Cambridge. 1899 Wood, Walter James, M.I.Mecb.E. Ernecroft, Ahhey-road, Grimsby, and 112, Cleethorpe-road, Grimsby. 1911 Woodhead, German Sims, M.A., M.D., LL.D., F.E.S.E., F.E.C.P. (Ed.), Professor of Pathology in the University of Cambridge. Dysart House, Luard-road, Cambridge. 1880 *Woodward, Bernard B., F.L.S., F.G.S. 4, Longfield-road. Ealing, W., and Brit. Museum {Nat. Hist.), Crom>i:ell-road, S.W. 1880 *Woodward, Henry, LL.D., F.R.S., F.G.S., F.Z.S. Tudor Cottage, Clay Hill, Bushey, Hert^. 1889 Wright, Charles Henry. 10, Clarence-road, Kew. 1882 Wright, Prof. E. Eamsay, M.A., B.Sc. Bed Gables, Headington-hill, Oxford. 1918 Yermoloff, Sir N., K.C.B., K.C.V.O., F.L.S. 3, Whitehall-court, S.W.I 1890 *Youdale, William Henry. 21, Belle Isle-street, Workington. 1918 Young, George William. 20, Grange road, Barnes, S.W. HoNOKAUY Fellows. 25 HONORARY FELLOWS. 1879 Balbiani, E. G. ' Paris. 1904 Bonnier, G. Paris. 1918 Bruce, Lady Mary Elizabeth, K.K.C. London 1904 Delage, Y. Paris. 1905 Farlow, W. G. Cambridge, Mass., U.S.A. 1895 Golgi, C. Padua. 1905 Jennings, H. S. ^ Baltimore. 1897 Lee, A. B. Cologny. 1912 Penard, Eugene. 1904 gRamon y Cajal, S. Madrid. 1879 Hanviev. L. Paris. 1902 Eayleigb, Kt. Hon. Lor.1, E.R.S. Londo7i. 1896 Eetzius, G. StocJcholm. 1879 Sars, G. 0. Christiania. 1904 Teall, J. J. H. London. 1897 Toni, G. B. de Modena. 1879 Warming, E. e Copenhagen. 1905 Wilson, E. B. New York. 1905 Wood, R. W. Baltimore. |latron HIS MAJESTY THE KING. ^ast-|lrcsitients. Elected *SiR Richard Owen, K.O.B. D.C.L. M.D. LL.D. F.R.S. 1840-1 ♦John Lindley, Ph.D. F.R.S 1842-3 *Thomas Bell, F.R.S 1844-5 *James Scott Bowerbank, LL.D. F.R.S 1846-7 *George Busk, F.R.S 1848-9 *Arthur Farre, M.D. F.R S 1850-1 *George Jackson, M.R.C.S 1852-.^. *WiLLiAM Benjamin Carpenter, C.B. M.D. LL.D. F.R.S. 1854-5 *Georgb Shadbolt 1856-7 *Edwin Lankester, M.D. LL.D. F.R.S 1858-9 ♦John Thomas Quekett, F.R.S 1860 ♦Robert James Farrants, F.R.C.S 1861-2 ♦Charles Brooke, M.A. F.R.S 1863-4 ♦James Glaisher, F.R.S 1865-6-7-8 ♦Rev. Joseph Bancroft Reade, M.A. F.R.S 1869-70 ♦William Kitchen Parker, F.R.S 1871-2 ♦Charles Brooke, M.A. F.R.S 1873-4 ♦Henry Clifton Sorby, LL.D. F.R.S 1875-6-7 ♦Henry James Slack, F.G.S 1878 ♦Lionel S. Beale, M.B. F.R.C.P. F.R.S 1879-80 ♦Peter Martin Duncan, M.B. F.R.S 1881-2-3 *Rev. William Hy. Dallinger, M.A. LL.D. F.R.S. 1884-5-6-7 ♦Charles Thos. Hudson, M.A. LL.D. (Cantab.), F.R.S. 1888-9-90 "Robert Braithwaite, M.D. M.R.C.S 1891-2 Albert D. Michael, F.L.S 1893-4-5-6 Edward Milles Nelson 1897-8-9 William Carruthers, F.R.S. F.L.S. F.G.S 1900-1 Henry Woodward, LL.D. F.R.S. F.G.S. F.Z.S 1902-3 DuKiNFiELD Hy. Scott, M.A. Ph.D. LL.D. F.R.S. F.L.S. 1904-5-6 ♦The Right Hon. Lord Avebury, P.C. D.C.L. LL.D, F.R.S., etc 1907-8 Sir Edwin Ray Lankester, K.C.B. M.A. LL.D. F.R.S. F.L.S. F.Z.S 1909 J. Arthur Thomson, M.A. F.R.S.E 1910-11 ♦Henry George Plimmer, F.R.S., F.L.S., F Z.S., etc 1911-12 G. Sims Woodhead, M.A. M.D. LL.D. F.R.S.E., etc 1913-15 Edward Heron-Allen, F.R.S. F.L.S. F.G.S., etc 1916-17 * Dftoeased, THE Established in 1839. Incorporated by Eoyal Charter in 1866, 20 HANOYER SQUARE, LONDON, W.l The Society was established in 1839 for the promotion of Micro- scopical and Biological Science by the communication, discussion, and publication of observations and discoveries relating to (1) Improve- ments in the conscruction and mode of application of the Microscope, and (2) Biological or other subjects of Microscopical Research. It consists of Ordinary, Honorary, and Ex-officio Fellows of either sex. Ordinary Fellows are elected on a Certificate of Recommendation signed by three Ordinary Fellows, setting forth the names, residence, and qualifications of the Candidate, of whom the first proposer must have persona] 'Knowledge. The Certificate is read at two General Meetings, the Candidate being balloted for at the second Meeting. The Admission Fee is 21. 2s., payable at the time of election ; and the Annual Subscription is 21. 2s., payable on election, and subsequently in advance on 1st January in each year, but the Annual Subscriptions may be compounded for at any time for 81^. 10s. The annual Subscription of Fellows permanently residing abroad is II. lis. Qd., or a reduction of one-fourth. The Council, in whom the management of the property and affairs of the Society is vested, is elected annually, and is composed of the Presi- dent, four Vice-Presidents, Treasurer, two Secretaries, and twelve other Ordinary Fellows. The Meetings are held on the third Wednesday in each month from October to June, in the Lecture Hall, at 20 Hanover Square, W.l (commencing at 8 p.m.). Visitors are admitted on the Introduction of Fellows. The business of the Meetings includes the reading of p^apers, the exhibition of microscopical objects and apparatus (usually on view by 7. 30 P.M.), lantern demonstrations, and discussions. The Journal is published quarterly. All Fellows are entitled to a copy, and it is also sold to Non-Members, at an annual Subscription of 42s. post free. It contains the Transactions and Proceedings of the Society, and a Summary of Current Researches relating to Zoology and Botany (principally Invertebrata and Cryptogamia), and Microscopy. The Library, with the Instruments, Apparatus, and Cabinet of Objects, is open for the use of Fellows daily (except Saturdays), from 10 A.M. to 5 P.M. It is closed for four weeks during August and September. Forvis of proposal for Fellowship, and any further information, may he obtained on application to tJie Secretary of the Society, 20 Hanover Square, London, W.l JOUENAL OF THE EOYAL MICEOSCOPICAL SOCIETY. MARCH, 1911). TRANSACTIONS OF THP: SOCIETY. I, — Presidential Address, 1917-18 : The Limitations of Microscopy. By Joseph E. Barnard, P.R.M.S. (Bead February 19th, 1919.) In accordance with long-established custom, the time has come for me to inflict on you a Presidential Address. I confess that the selection of a suitable subject confronted me with a problem of some difficulty. I turned for inspiration to the subjects of addresses by some of my predecessors, to find that they in most cases dealt with the particular branch of microscopy in which they were interested, and relied on their, often great, literary ability to put before you an exposition which was a worthy addition to the publications of this Society. My only course appeared to endeavour to the best of my ability to follow such an example, and to deal with some special branch of microscopy ; but with the cessation of war I realized that a change in our outlook must of necessity take place — that I was in a position that none of my predecessors had ever found themselves in, having regard to the social and scientific possibilities of the period ahead of us. It is no longer possible to regard anything as established beyond all chance of reform. The spirit of regeneration is in the air, and it behoves us as a scientific society to review the situation, and to make sure that the branch of science in which we are interested is on a sound foundation, and that we are worthily repre- senting its interests. I felt, therefore, that some review of the present state of microscopy, its limitations, and, if I dare be prophetic, its possi- bilities, was called for. Let me at once disclaim any intention, or B 2 Transactions of the Society. for that matter any ability, to tell you something new. It will be of necessity a repetition of an oft-told story, but not I trust entirely devoid of interest even to those of us to whom it is most familiar. There is in this Society perhaps too great a disposition ta avoid what is elementary. I can hardly imagine that any of u& are so well grounded in the principles of microscopy that no further consideration is necessary. In fact the exhibits here from time to time convince me that while the objects are often of great interest, the methods of showing them do sometimes leave much to be desired. That will only be remedied by an educational effort, so that all of us may have the opportunity of understanding the scientific principles of the subject we are interested in, and of applying those principles in all we undertake. This, then, is my excuse for dealing with the elements of the subject at this time. It may be only an excuse, and not a well-founded argument, but I can assure you that it has at least the merit of being honest in intention. I need hardly remind you that I shall be unable, with the time available, to do more than glance here and there at general prin- ciples, touching on and indicating points of interest, but not dealing with any part of my subject in a comprehensive or exhaustive manner. In any consideration of the limitations imposed by the micro- scope, a clear conception of the magnitudes involved and the relation of microscopic resolution to wave-lengths of light and to molecular dimensions is necessary. This point is of importance, because while the limits of resolution are deiinite, and unfortunately soon attained, the limits of visibility are by no means so inflexible, and lead us to a consideration of bodies that may approach an organic molecule in order of size. As you are all aware, the unit of measurement which is usually adopted in microscopic work is the micron, represented by the Greek sign fi. In observations that involve a consideration of dimensions comparable to wave-lengths of light it is more con- venient to adopt the micro-millimetre, which is one -thousandth of a micron, and which therefore bears a convenient relationship to dimensions that are of a much smaller order of size. I know of no more graphic method of demonstrating the relative size of these various dimensions than that adopted by Sir George Beilby when dealing with the thickness of thin metal films, and the diagram I am showing you, and the description I give, are taken from his monograph on the " Surface Structure of Solids." Beginning on the left there is a scale in micro-millimetres. Next to this are three bars which represent on the same scale tlie wave-lengths of mean red, mean green and mean violet light respectively. The centre of the diagram is occupied by a series of seven sections, all on the same scale, of leaves or films of Presidential Address. 3 thickness varying from 1 micro-millimetre up to 360 micro- millimetres. The three black bars on the extreme right represent on the same scale the resolving power of the three microscope objectives with which we are, perhaps, most familiar, and which are to be found in most batteries of objectives that are used for accurate work. The numbers at the lower ends of the bars are the numerical apertures of these lenses. " Taking the third of the series, which is marked as having a numerical aperture of 1'4, its length is about 150 micro- millimetres. This means that if two lines were ruled on a glass plate, 150 micro-millimetres apart, they would be seen as two distinct lines by means of this lens. With either of the other two lenses the lines would merge into one : the lens would fail to resolve them." " The diagram shows at a glance that an object may be visible to the unaided eye, even though one of its dimensions is far below the range of microscopic resolution. For example, the thickness of a gold-leaf is about 90 micro-millimetres — that is to say, it is 60 millimetres below the resolving power of a lens of 1*4 N.A. Yet we can see the surface of a leaf with the unaided eye, and can examine it microscopically without difficulty ; but if we try to see the edge of the leaf we shall fail, for instead of the real edge we shall see an ill-defined edge, the apparent width of which would entirely depend on the aperture of the lens used. With a 1 * 4 lens the apparent width will be 150 micro-millimetres; with an 0*65 it will be 300 micro-millimetres ; and with an 0*3 it will be 700 micro-millimetres. The obvious lesson from this is that in using the microscope in this region of micro-dimensions, we must be careful to keep its limitations, and their possible effect, always in mind." In any consideration of the limits of resolving power we have to remember that whenever image-formation by a lens-armed aperture takes place the resulting image of a point is no longer a single point, but a circle of light surrounded by diffraction rings. The result is that in the microscope every optical appliance avail- able must be employed at its best, and optical accuracy of the highest order must be attained to ensure the production of a correct image, one in which these diffraction fringes are least in evidence. If we consider the observation of two objects, or elements in an object, then we shall fail to resolve them if they are so close together that the diffraction image from one overlaps that from the other. The same applies to a grating or series of contiguous points in an object, except that Johnstone Stoney has shown that two points in an object may be somewhat closer together and yet be resolved than the lines of a grating which are of the same distance apart. Also that two such objects would appear to be somewhat farther apart than they actually are. This important B 2 4 Transactions of the Society ' point, which it should be remembered is often brought home to the worker with the microscope, more often perhaps than any other, was first determined theoretically, and afterwards was proved in practice to be well-founded. The method of practical proof was by means of a Grayson ruling. By a fortunate chance two of these lines in the latter projected beyond the rest, so that a pair of objects of known distance apart could be observed. By gradually reducing the numerical aperture of the observing objective, it was shown tliat the projecting parts of the lines could be seen as two separate objects after the remaining rulings were ubliterated, and that they appeared to be farther apart than the distance between the rulings. As you are aware, the theory enunciated by Abbe, and known as the diffraction theory, takes a grating as a typical object. From this we know that the two factors determining the limits of resolving power are the numerical aperture of the objective and the mean wave-length of the light used. Under the most favourable circumstances then the practical limit is reached when objects in a row are about '20^11 apart, or a pair of objects can be differentiated when they are about five-sixths the distance apart of those that can be separated, if they are in a regularly recurring series. These limits of resolution for two separate objects may also be taken as the absolute limit of resolution for an isolated object that can be seen and observed as a definite entity. It represents, in fact, the smallest object we can see as a dark body on a bright ground, while being able to ascertain its definite form ; but it does not by any means represent the limit of visibility. This point is essentially different, and brings us to a consideration of bodies which can be observed as self-luminous ones on a dark background. The method is well known enough, and when it involves the observation of objects which are well within the resolution limits is referred to as dark-ground illumination. When an object is rendered visible which is small in all dimensions in comparison with a wave-length of light, the object is said to be ultra- microscopic. Lord Eayleigh has shown that the limits of visibility are dependent on the difference of refractive index between the object and the medium in which it lies, and on the intensity of the illumination. Under conditions which result in the object becoming a self-luminous one, it is therefore difficult to assign a definite limit to visibility. In the case of metals like gold and silver in the colloidal state, in which the refractive . index differs greatly from that of water, the medium in which they may be immersed, the limit of visibility depends on the amount of light that can be concentrated on such particles and on their separation. On the other hand, in the case of certain organic colloids, such as albumen, the particles are not easily made visible, because of the small difference of refraction existing between them Presidential Address. 5 and the medium. The limits of visibility are therefore mainly dependent on the intensity of illumination. Using sunlight as the illuminant, the smallest observable particle of colloidal gold is probably of the order of 5 micro-millimetres in diameter, and this may be taken to represent the smallest object that has been observed. It is, however, important for us to remember that colloidal gold is highly refractile, and therefore the conditions obtained when it is the observed material are equalled by but few other substances. It has been determined by calculation that the molecules of certain albuminoids have a diameter of 6 micro- millimetres. "Were these of the same optical character as colloidal gold they would therefore be visible, but for the reasons I have already indicated they remain invisible, and are likely to be so until some new method, founded on new principles, is established. The observation of gas molecules is at present much beyond the range of the ultra-microscope ; but as the result of a large number of microscopic observations Perrin has demonstrated that in an emulsion of gamboge, the granules being uniform in size, the distribution of the granules at various depths is in accordance with the law connecting the density of gases with their pressure. I am showing an ultra-microscope here to-night, with such granules in a new type of cell which simplifies manipulation very considerably. Such are very briefly the instrumental limitations in micro- scopy at the present time, in which theory and practice, within the limits of experimental error, are in agreement. In no optical instrument perhaps has a nearer approach to the theoretical possibilities been attained in practice. The wave theory of light has been the basis of all calculations, and has proved sufficient for our purpose. It has been fruitful in results, but there is no finality even in this, and it is as yet impossible to say where the present suggestions in physical science of a corpuscular basis to account for energy transmissions may lead us. In any case it would be an immense gain if the Fellows of this Society would more generally follow the advances in physics, at least in their elements. In this direction progress is rapid, and as it is dealing with the fundamental principles governing all processes, even vital ones, the necessity of a rudimentary acquaintance with such principles will become more and more necessary. The recent publication of such a book as that by Prof. Darcy Thompson on " Growth and Form," intensely interesting in itself, is even more fascinating because of the suggestions thrown out, and the possibilities it opens up. If I may give a simple illustration of what I mean, the usually accepted method of indicating the path of rays through an optical system may suffice. In nearly all text- books light is assumed to travel in straight lines, and so far as it indicates the main direction of propagation in a homogeneous 6 Transactions of the Society. medium the method is accurate. But in microscopic optics the importance of diffraction is now universally recognized, and as you know full well this is the very case in which light does not travel in straight lines, new wave centres are continually being set up. I remember hearing Lord Kelvin say that he had no interest in any theory, however ingenious it might be, in which he could not visualize the processes as they were assumed to occur. In our case the conception of light in terms of wave-fronts, plane, concave or convex helps us enormously. The fact that the interposition of any lens results in a change in the form of wave-front appears to me to simplify the matter. I might pursue this theme far beyond the accustomed limits of a Presidential Address, but time will not permit. Even at the risk of some repetition we may briefly summarize the position. Kesolution is dependent on the effective numerical aperture of our observing system, and the mean wave-length of the illuminant. By the use of a solid cone of illumination it follows that we can resolve structural elements of the order of 3 /i apart, and that by the use of oblique light this interval can be halved. In the latter case, however, we are unable to do much more than determine the periodicity of the structural elements, the microscope behaving as an interferometer. The resulting image cannot be regarded as a representation of actual structure, in fact we can go so far as to say that the image bears only a quantitative relation to structure. The resolution of diatoms, therefore, by means of narrow oblique beams, the only practical application that this method has, may be an interesting experiment in physical optics, but it is not microscopy. Visibility may be secured under the most favourable conditions of a particle of the order of 5 micro- millimetres in diameter, biit the resulting images of objects, rang- ing in size from the limits of resolution to the limits of visibilitv, are not sucli that any idea of form or condition can be established. It is merely a proof that the object exists ; other physical tests must be applied to approximately determine their size and state. As I have an ultra-microscope here to-night, perhaps a brief account of it may not be devoid of interest. It is not a novelty to most of those present, but to some it may be unfamiliar. In principle it is founded on the work of Faraday and Tyndall, a point which we may regard with legitimate pride, although it is no exaggeration to say that the great majority of advances in micro- scopy have originated, at lease in principle, in this country. In 1903 Siedentopf and Zsigmondy introduced the ultra-microscope in the form we are conversant with at present, in which the Tyndall cone is examined by means of a high-power microscope objective. The effectiveness of the appliance is dependent on the concentration of a great quantity of light on a small area, so that only a few of the particles in the field of view are illuminated. The illumination Presidential Address. 7 of the particles in depth is also controlled, to ensure that none above or below the focal plane of the observing objective are brought into view. The microscope is now a tool found in nearly all laboratories devoted to scientific research, and in that sense its applications are almost universal. But the ultra-microscope is a definite link between the physicist and the microscopist ; the method is micro- scopical, but its applications are mainly physical. The use of ultra-violet light and other radiations in microscopy also demands some physical knowledge. Without some acquaintance with spectroscopic methods for instance, I fail to see how any worker could succeed. We see therefore that in those directions in which advances are probable the physical aspect is in evidence, and may become predominant. Microscopy is not alone in this respect ; physics threatens or promises, as we choose to regard it, to dominate the whole range of scientific thought and effort. There is I think nothing to regret in this, rather should we regard it as a natural evolutionary process. When we know that the molecular structure of crystals can now be determined with accuracy by means of X-rays, it may help us to realize that the term " microscopy " may mean something quite different in the future to what we now understand. It is simply a question of keeping our minds open and in a state of flexibility, to enable us to rearrange our ideas to conform to new conditions. The following is a description of the early experiments by Tyndall, which I feel sure will be of interest, as it indicates so clearly the line of thought that can be attributed to him : — It has been long known that light effected the decomposition of a certain number of bodies. The transparent iodide of ethyl, for example, becomes brown and opaque on exposure to light, through the discharge of its iodine. The art of photography is founded on the chemical actions of light ; so that it is well known that the -effects for which the foregoing theoretic considerations would have prepared us are not only probable but actual. But the method now to be followed, and which consists simply in offering the vapours of volatile substances to the action of light, enables us to give a vast extension to the operations of light, or rather of radiant force, as a chemical agent. It also enables us to imitate in our laboratories actions which have been hitherto per- formed only in the laboratory of nature. The substances chosen for examination are so constituted that when their molecules are broken up by waves of light the newly-formed bodies are com- paratively in volatile. To keep them in the gaseous form these products of decomposition require a higher temperature than the vapours from which they are derived ; hence, if the space in which these new bodies are liberated be of a lower temperature than that requisite to maintain the vaporous condition, they will be precipi- 8 Transactions of the Society. tated, as clouds, upon the beam, to the action of which they owe their existence. The simple apparatus employed in these experiments will be at once understood by reference to illustration. SS' is a glass experi- mental tube, which may vary from 1 to 5 feet, with a diameter of 2 or 3 inches. From the end the pipe 'pP passes to an air-pump. Connected with the other end is the flask F, containing the liquid whose vapour is to be examined. Then follows a U-tube T', filled with fragments of marble wetted with caustic potash. The carbonic acid of the air is here removed. Finally comes a narrow tube tt\ containing a tolerably tightly-fitting plug of cotton-wool. This. intercepts the floating matter of the air. To save the air-pump gauge from the attack of such vapours as act upon mercury, as also to facilitate observation, a separate barometer-tube is employed. The experimental tube SS' being exhausted, a cock at the end S' is carefully turned on. The air passes slowly through the cotton- wool, the caustic potash and the sulphuric acid in succession. Thus purified, it enters the flask F, and bubbles through the Jiquid. Charged with vapour it finally enters the experimental tube, where it is subjected to examination. The lamp L, placed at the end of the experimental tube, furnished the necessary beam. We will now permit the electric beam to play upon the invisible vapour of nitrite of amyl. The lens of the lamp is so situated as to render the beam convergent, the focus falling near the middle of Presidential Address. 9 the tube. You will notice that the tube appears empty for a moment after the turning on of the beam ; but the chemical action will be so rapid that attention is requisite to mark this interval of darkness. I ignite the lamp, and a luminous white cloud immedi- ately falls upon the beam. The beam has, in fact, shaken asunder the molecules of the nitrite of amyl, and brought down upon itself a shower of particles which flash forth like a solid luminous spear. This experiment, moreover, illustrates the fact that however intense- a beam of light may be it remains invisible unless it has something to shine upon. Space, though traversed by the rays from all sun& and all stars, is itself unseen. Not even the ether which fills space,, and whose motions are the light of the universe, is itself visible. It is possible to impart to these clouds any required degree of tenuity, for it is in our power to limit at pleasure the amount of vapour in our *experimental tube. When the quantity is duly limited, the precipitated particles are at first inconceivably smalL defying the highest microscopic power to bring them within range of vision. Probably their diameters are then not greater than the- millionth of an inch. They grow gradually, and as they augment in size they throw from them a continually increasing quantity of wave-motion, until finally the cloud which they form becomes so luminous as to fill a room with light. During the growth of the particles the most splendid iridescences are often exhibited. It is- not however with the iridescences, however beautiful they may be,, that we have now to occupy our thoughts, but with other effects- which bear upon the great standing enigmas of meteorology — the colour of the sky and the polarization of its light. The blue light of the sky is scattered light ; and were there nothing in our atmosphere competent to scatter the solar rays, we should see no blue firmament, but the mere darkness of infinite space. The blue of the sky is produced by perfectly colourless- particles. Smallness of size alone is requisite to ensure the selection and reflexion of this colour. It is possible, as above stated, by duly regulating the quantity of vapour, to make our precipitated particles grow from an infini- tesimal and altogether ultra-microscopic size to specks of sensible magnitude ; and by means of these particles, in a certain stage of their growth, we can produce a blue which shall rival, if it does not transcend, that of the deepest and purest Italian sky. Here, then, we have the fundamental principles governing ultra- microscopic methods and processes, a truly remarkable example of scientific originality and foresight. We know in practice that under conditions which secure the same magnification, the same methods of illumination, and similar cor- rections of aberrations in the objective, the best definition and highest resolution is always secured by the lens with the highest numerical! aperture. Further, we realize that a reduction in the mean wave- 10 Transactions of the Society. length of the light used is of value. In terms of N. A. a reduction in wave-length of the illuminant from 550 micro-millimetres to 450 micro-millimetres is equivalent to an increase of the aperture from 1"40 to 1"70 approximately. The most luminous part of the spectrum is the region about 550 micro-millimetres wave4ength. In prac- tice the use of screens or other devices which cut out this part of the spectrum seriously reduces luminosity, so that it is necessary when experimenting with colour-screens to have a variable illumi- nant so that an increased emission of light may be secured to compensate for the inevitable reduction in luminosity. I have reason to believe that this factor, and the varying sensitiveness of the eyes of different observers to different regions of the spectrum, accounts for the variation in results obtained by the use of colour- screens ; but in my own case I find such methods invaluable. I . am afraid I have taken up too much time with generalities in con- nexion with ultra-microscopy, but I feel sure that this branch of work has a great future before it. It is usually regarded with a certain amount of awe by the average worker, but I can assure you such an attitude is not justified. It has difficulties certainly, but they are easily mastered. The instrumental needs are not great, and anyone with a taste in that direction could improvise an efficient apparatus without difficulty. In another direction, the use of ultra-violet light and other short radiations, the possibilities are even greater. I have already brought this branch of work before this Society on several occasions, so I will content myself by showing you a few slides of later results. The work has been almost stopped during the war, but I am in hopes of continuing my experiments almost immediately. To most of us, however, are the limitations I have referred to, the absolute limits that our microscope can attain, the ones we are continually or even occasionally confronted with ? I think not. Most of us are confronted with difficulties owing to our failure or inability to take full advantage of the facilities that the microscope offers to us. To obtain the utmost efficiency in ordinary every- day practice the conditions with which we have to comply are relatively simple and few. Firstly, we must have a solid cone of illumination which is sufficiently large to utilize the utmost possible working aperture of our objectives. Secondly, all the optical systems employed, whether objective, eye-piece, or illumi- nating system, must have their optic axes in exact alignment. Tliis condition of affairs is known in this Society, but not so widely outside it, as critical illumination. In this connexion it is interesting to note that any want of •decentration, if it is only in a lateral direction — by that I mean that the optic axes remain parallel, but are not co-incident — is not so serious as a deflection of one optic axis, so that it is no longer parallel but inclined to the axis of the microscope. Presidential Address. 11 It is obvious, therefore, that the utmost care should be taken to ensure accurate centration, as on this, more than on any other one factor, correct image formation is dependent. The selection of a suitable light source is also of considerable importance ; not only should the illuminant be of such a character that it can be used for any purpose, but it should be so arranged that the intensity can be varied quite apart from any adjustment of the iris-diaphragm of the sub-stage condenser. It is often possible to use a substantially larger cone of illumination if the intensity of the light is suitably moderated. This is particularly evident in dark-ground illumination work, in which it is possible to utilize an ol)jective of considerably greater numerical aperture if the illuminant is not of too great intensity. We all know what is meant when critical illumination is referred to, and there is no necessity for me to go over the ground again. It has been well covered by others more able to deal with it than myself. But I must make some protest against the differentiation between so- called critical illumination and illumination which, for want of a better term, I must refer to as non-critical. What is critical illumination after all? Simply the application of well-known optical principles in a proper manner. Nothing more. Is there any other optical instrument of any complexity in the use of which some special term has to be applied when the conditions are fulfilled for obtaining a correct image ? Tliis is really what we do in microscopy. We apply this term of critical illumination to a . state of affairs where we are simply doing things properly, and we are content therefore, when not using critical illumination, to put up with a state of affairs that is not in accordance with optical principles, and that we know perfectly well cannot give us an accurate image. I shall be very glad to know that the term has been dropped at least in this Society, not because I have anything at all to say against the method or the procedure — on the contrary, I think there is everything to be said for it — but we should not adopt a special term to describe a process which is merely the performance of a routine method in a scientific manner. Before I conclude may I say one word in reference to the Society itself ? When you honoured me by electing me as your President, whilst fully appreciating the honour, I felt that the responsibility was considerable. At the time we were at the very worst stage of the war, with all its discomforts and possibilities. I realized that the period must be one of difficulty, but I think it is a tribute to this Society that we have passed through it so well, and without any results that could be regarded as serious. The attendance at the Meetings has been quite satisfactory, and the Fellowship has kept up to a remarkable degree. There is one outstanding service that has been rendered to us during 12 Transactions of the Society. the past year, and that is the re-arrangement and organization of the Cabinet of Slides by Messrs. Earland and Shepherd. It is difficult for those of us who were not at least in partial contact with this work to realize what it involved, and the close application that it entailed. It should be appreciated that this Cabinet is of considerable value, and one to which the Fellows would do well to refer to a much greater extent. Some of the slides are unique, others are of great historic interest, while all, as the result of selection and re-arrangement, are well worth consideration. It was found, however, that at present there are hardly any workers devoting their attention to the structure of diatoms. Those of us who read the back numbers of our Journal know that many optical improvements in the microscope have taken place as a result of the demand which has been put forward by diatom workers; In endeavouring to re-arrange the slides in the Cabinet of this class it was difficult to find any Fellow with the requisite knowledge who could devote the necessary time to the purpose. I am sure that this is a matter of regret to many of us, and I appeal to those who are not fully occupied with other researches to make an effort to regain for the Society the pre eminence it once enjoyed in this direction. Bacteriology is another branch in which I should like to see more work done. It is, I think, erroneously assumed that this involves the use of elaborate laboratory equipment, but a con- siderable amount can be done with simple apparatus. There is the further point that it generally demands the use of optical appliances and high-power objectives which, to get the best results, must be used at their best. Take, for example, the work that has re- cently been published in connexion with a group of organisms, if I may refer to them as such, known as " filter-passers," particu- larly in connexion with trench fever, influenza, and other diseases. On the microscopic side, it is at the very limit of what the finest objectives are capable of doing, using them at their best. But the average bacteriologist rarely takes full advantage of the appliances availal)le, I will not labour the point, but I trust that I have said enough to indicate that there is work to be done, and that the expert microscopist is the one to do it. Perhaps our greatest need at the moment is for more convenient and better-equipped premises. Our meeting-room is not all that we could wish, and we certainly need better accommodation for the library and instruments. We should have some equipment so that microscopic work of the highest class could be done here, or at least in close connexion with the Society. We should encourage younger men to enter, so that the enthusiasm of youth might act as an antidote to the undue caution of maturity. It might even be advisable to consider the institution of a class of membership which would be open to the young university student or graduate, carry- Presidential Address. 13 ing with it the opportunity of attending meetings and the possession of the Journal for a nominal fee. From these we should be able to recruit a large body of Fellows while giving encouragement and help to some at the time they need it most. It would be well if we could do as most other scientific societies of standing do : establish one or more memorial lectures to commemorate those worthy of it. Our records show that there would be no difficulty in furnishing names of those whose work deserves to be remembered for generations to come. As it is, the results of their efforts remain, and is a memorial in itself, but it might be made an even brighter example to those following if it were periodically reviewed. In conclusion, I should like to take this opportunity of thank- ing the Fellows of the Society for the courtesy and consideration which they have shown me. I am also deeply grateful to the Officers of the Society for their unvarying support. I need hardly ^ say that without an efficient and unselfish staff of Honorary Officers, such as we possess, the Society could hardly exist. There is at least no controversy on one point. We are able to hold our annual general meeting without the accompanying horrors of war. For that we unite in deep thankfulness. 15 II. — Eye-pieces with Adjustable Compensation. By H. Hartridge, M.A., M.D, F.RM.S., Fellow of King's College, Cambs. {Read December 18, 1918.) One Diagbam, The importance of completely eliminating chromatic difference of magnification has been dealt with in my investigations into the resolving power of the eye {!)* for I found that the presence of this defect had a markedly detrimental effect on definition at the fovea centralis of the eye. Now, as is well known, m'icroscopic objectives vary greatly in the amount of chromatic difference of magnification which they exhibit. In some combinations the aberration is practically absent, in others (particularly apochromatic objectives of high power) its complete elimination is difficult, if not impossible, while between the two extremes are found a large number which form the semi- apochromatic class. There is thus found a considerable variation between the amount of correction which different objectives require, and the case is not properly met, therefore, by the provision of two sets of eye-pieces only, namely, compensated and uncompensated; it is necessary, in addition, that the amount of compensation may be varied so that complete correction may be obtained in every case. The Holoscopic series of eye-pieces, which possess this property of adjustable compensation, are found at the same time to suffer from disadvantages, for not only is change in compensation accom- panied by change in position of the lower focal plane, and therefore change in focus of the objective, and change in tube length (accompanied by the introduction of spherical aberration), but also a change in the magnification is found to take place. Now, although the new Holoscopic eye-pieces are better in this respect than the old, still the disadvantages remain, but in a reduced degree. Further, as the Holoscopic eye-piece is of the Huygens type the Ptamsden circle is close to the upper surface of the eye lens. This, in high powers particularly, causes inconvenience owing to the closeness of the eye to the top of the eye-piece. A number of experiments have been made in order to obtain an eye-piece which, while providing adjustable compensation, does * The italic figures within brackets refer to the Bibliography at end of the paper. 16 Transactions of the Society. not suffer from the above-mentioned defects. Four typical members of the series have been designed and two actually •constructed. Tests of these have shown that the elimination of the difficulties' above mentioned has been effected with complete success. The construction of these eye-pieces may be briefly described as follows :— In all powers the top combination is fully achromatized, whether it be a simple doublet or a more complicated system. Similarly in all powers the compensation is provided by a combination of crown and flint glass lenses, which are of equal and opposite power, so that the whole has no focus for rays in the middle of the spectrum. Eays of short wave length are, however, laent towards the axis, while rays of long wave length are bent ■away from it. This causes images produced by violet and blue rays to be decreased in size, and images produced by red and orange rays to be increased, relative to images formed by yellow and green rays. Suppose the a-focal combination to correspond with the plane •of the virtual image formed by the objective, then it is clear that no change in the relative size of the images produced by different ■coloured rays has been produced, and the eye-piece is therefore uncompensated. As the a-focal combination is placed further from the image plane, so the relative size of the images is changed. Thus, if it be placed between the image and the eye, then violet images are magnified and red images are diminished (and the eye- piece as a whole becomes more uncompensated) ; if, on the other hand, the combination be placed below the image (in between the 'Objective and its image), then the effect on the images is reversed and therefore compensation is introduced, the amount of which varies with the distance between the virtual image and the ■combination. If in the a-focal combination the negative lens is of flint glass and the positive of crown, then the effects are the reverse of those K w 5: 1 03 O kj 0) ^ ^ iil ^ r 5! ^ 5 1 ^ 0: t ^ Vj w t ci ^ {Records Indian Museum, 1919, 15, 841-4, 1 pi.). In artificial con- ditions specimens of Anahas scandens may show colloid carcinomas over the surface of the body. They consist of tissue of a thyroid nature, and are rounded structures with a smooth surface. It is impossible to say whether they are directly developed from cells of the thyroid gland or not. A specific organism is suspected, but as yet none has been isolated. J. A. T. c. General. Deep-water Fauna of Lake Neuchatel. — A. Monard (Revue Suisse Zool, 1918, 26, 341-59, 21 figs.). A survey begun in 1916 has already yielded 350 species. Some are quite new, such as a Halacarid genus, Soldanellonyx (with two species), three new species of Nematodes, a Bdelloid Rotifer, a Cladoceran, and so on — seventeen new species altogether. Monard reports on Epistylis violacea sp.n. (on the head of Chironomid larvae), Cothurniopsis canthocampti sp. u. (borne by Gantho- camptus), a Rotifer {CalUdina proyonidea sp.n.), a Daphnid (Peracantha fuhrmanni sp. n.), and a new variety of Canthocamptus sfaphylimis. The deep-water fauna is turning out unexpectedly rich. J. A. T. Fauna of Eichener Lake. — R. T. Muller (Rev. Suisse Zool, 1918, 26, 361-408, 3 figs.). An account is given of the environmental conditions in this lake and of its fauna. The list includes about tliirty Rhizopods, the interesting Helizoon Raphidiophrys intermedia Pen, about nineCiliata, fifteen Rotifers, three Nematodes, three Chfetopods, Pluma- iella reptans, three species of Macroliotus, about a dozen insects, one Phyllopod (the interesting Tanymastix lacunae Guerin), two Ostracods, ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 33 Cyclops strenuus, four Amphibians, and a wild duck. Tlie fauna is marked as a whole by the capacity of its components for lying quiescent in the mud or the like during unpropitious conditions, such as drought. J. A. T. Colours of Reef-flshes. — W. H. Loxgley {Proc. Amer. Soc. Zool. in Anat. Record, 1919, 15, 350-1). West Indian and Hawaiian reef- fishes are protected by general colour and pattern. A new observation records the fact that some change their coloration as they rise vertically, leaving the bottom and its influence. This is adaptive, like the change of colour associated with horizontal movement. " Nuptial coloration " may be sometinies an index of changed location at that period. J . ix. J- • Reaction of Fishes to H-ions. — Y. E. Shelfoed {Proc. Amer. Soc. Zool. in Anat. Record, 1919, 15, 347). Experiments show thatmany marine fishes are exceedingly sensitive to minute differences in the concentration of hydrogen ions. The Pacific herring reacts negatively to 0*8 part per million of sulphurous acid (H2SO3) in a manner which indicates an ability to distinguish 0*6 part per million. In this case the difference in H-ion concentration is very slight, probably too slight to be distinguished. Reactions to other chemicals indicate that small amounts of other ions may predominate over small H-ion concentration. Are there Varieties of Eel ?— 0. Nordqvist {Ar¥iv Zool., 1917, 11, No. 6, 1-22). The application of biometric methods to a large body of measurements of the common eel {Angudla angidlla) shows that there are considerable differences in the proportions of the body in the two sexes and at different ages. But as regards the existence of narrow-headed and broad-headed varieties the author's results are negative. He points out, however, why he is not prepared as yet to give an answer in the negative. J- A. T. Pelvic Structure and Burrowing Habits. — Royal Norton Chapjian {Amer. Journ. Anat., 1919, 25, 185-219, 5 pis.). In moles there are horizontal pelves firmly co-ossified to the vertebral column, the ventral margins of the pubes are horizontal and diverge posteriorly, and there is no pubic symphysis. In gophers the same holds, but the symphysis is present in the males and some females. In the marsupial mole the pelvic bones are co-ossified firmly to the vertebral column, the pelvis is horizontal, and the symphysis is greatly reduced. A horizontal pelvis firmly fused to the vertebral column, and the reduction or absence of symphysis, may be correlated with the mechanical force exerted by the hind limbs in propelling the body in continuous burrowing. The horizontal position of the pelvis transmits the locomotive force exerted by the hind limbs along a straight line from the articulation of the limbs to the anterior part of the body. In a similar way the author interprets the reduction of the symphysis, its retention in the pocket gophers, the broad and narrow pelves, the crossing of the rectus abdo- minis muscles, and so on. From a number of variations in each group D 34 SUMMARY OF CUEEENT EESEARCHES EELATING TO of burl•o^vers the most efficient structure has probably been established by natural selection, but ^Yith this interpretation the author Tvould combine the idea that similar forces acting in a similar "uay have been factors in causing similar modifications of structure in animals belonging to widely different groups, just as tuberosities develop on bones at the points of attachment of muscles of strenuous action. J. A. T. INVERTEBRATA.J ^ Mollusca. * a. Cephalopoda. Luminescence ofWatasenia scintillans. — Rinnosuke Shoji {Amer^ Joiirn. PliysioL, 1919, 47, 534-57). In this Japanese luminous squid the luminescence is intracellular in three sets of structures. The lumi- nescence is due to an oxidation. Alcohol, ether and chloroform inhibit the luminescence in a few minutes, though in the first stage of the process they excite the production of light to a certain degree. The power of illumination is quickly recovered on the removal of the narcotics. The most favourable temperature for luminescence is be- tween 1G° and 81° C. ; direct sunlight has no influence on it ; the effect of other environmental factors has been experimentally determined. J. A. T. 4- ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 51 BOTANY. GENERAiL, Including- the Anatomy and Physiology of Seed Plants. Cytology, Including- Cell-contents. Significance of the Chondriome. — A. Guillieemond {Rev. Gener. Eotan., 1918, 30, 161-76, 13 pi.) publishes a further paper in support of his theories as to the origin and nature of the chondriome. The author claims that the elements of the chondriome, i.e. the mitochon- . Zinssmeister {Phytopathology, 191H, 8, 557-71, 8 figs.) has investigated diseased roots of Ginseng {Panax qvinquefoiinm). The disease has been known as a root-rust, but the author has traced it to the Ramularia fungus. He has examined the tissues, in which he has traced the course of the disease, and he has made cultures and inoculations. He describes three new species of Ramularia which he has isolated. A. L. S. Pink Disease of Plantation Rubber.— This disease has been abundant in Malayan Estates since 1912, and F. T. Brooks and A. Sjiari'LKS {Ann. Ap/i. Biol., 1915, 2, 58-80, 11 figs.) have investigated its distribution, hosts, etc. It is due to the fungus Corticium. salmonicolor, which may exist in a sterile condition. It affects both the bark and the wood, inducing tyloses in the vessels of the latter. Instruction is given as to treatment. A. L. S. ZOOLOCIY AND I'.OTANY, MICUOSCOl'Y, ETC. 71 "Black Neck," or Wilt Disease of Asters. — W. Robinson {Ann. App. JlioL, r.)15, 2, l^;")-;^?, 2 pis.) found that this fungus was due to a species of Fhytophthora, possibly a physiological form of /\ omnivora. The sporangia are peculiar in that the stalk grows through the sporan- gium after the discharge of the zoospores and forms a second and even a third. No sexual organs were observed. A. L. S. Silver-leaf Disease. — T. Smolak {Ann. App. Biol., 1915,2, ISS-fjI, 11) figs.) investigated the cytology of leaves attacked by this disease. He describes the changes induced, resembling those found in gall-tissue. He does not consider that the disease is in all cases due to Stermm pHr2')nreum, nor does he think the silvering is caused by an enzyme ; more probably a toxin is secreted in the leaves, which causes the changes which he describes. A. L. S. Tomato-fruit Rots. — These fruit-rots, according to .1. RosKNP.AU.'vf ( Phylopatholoijij , i;)18, 8, 572-81, 1 pi.), do not originate in transit as was supposed, but have been traced to Held infection, though the trouble may spread in transit. Over-ripeness of the fruit is favourable to the development of the rot fungi. He finds three types of rot : (1) Buckeye Hot {Fhytophthorti terrestria), which can spread to adjacent uninjured fruit ; (2) Soil Rot {Rhizoctonia sp.). White Hot {Sclerotium Rolfau), and lieak {Rkizopuf< sp.), (the fungi of this type infect through the stem end or through some break in the skin) ; (a) Nail-head Spot {Macrosporium Solani), Black ^^ot {Phoma dedructiva), and Anthracnose {Golletotrichvm phomoides) — these do not affect healthy adjacent fruit. A. L. S. Some Potential Parasites of the Potato Tuber. — T'liere are a number of saprophytic i'ungi, niaiidy Hyphomycetes, that are fi-efjueutly found on potatoes in storage. M. Siiapovalov {Phytopatholoyy, 1919, 9, 36-42, 2 pis., 2 figs.) has demonstrated that these fungi may be- come parasitic and cause considerable damage. The fungi under observation were FenicilUum oxalicam, Asperyillus niyer, and (Jlono- stachys araucaria var. r.oma. The author compares the rot caused by these moulds with the damage done l)y Fmarium radicicola, a serious wound-parasite of the potato. The lesions made by Asperyillufi niyer were almost as deep as those made by the Fmarium. in the same time ; those by the FenicilUum a little less so, while those by GlomMachys lagged some way behind. He found, however, that the Asperyillus was less likely to cause infection than the Fenicillium. A. fi. S, Diseases of Yams. — The yam affected, iJiscorea prehensilis, was collected in Nigeria and sent to Kew for examination. E. M. Wake- field {Kew BiUL, 1918, 199-201, 1 pi.) found that the cause of the disease was a fungus belonging to tiie geims y>'a///w'.s7'o;?.s-<.s-(Dothideacete). It attacks isolated branches of the yam-vine, blackening and destroying them ; the internodes are shortened and the leaves dwarfed. A diagnosis of the fungus B. Dioscorese is given. A. L. S. 72 SUMMARY OF CURRENT RESEARCHES RELATING TO Disease of Cabbage. — M. P. RB^Bmif^oi^ (Phytopathology, 1918, 8, 379-431, 10 figs.) has made a thorough study of a disease of the leaves, stems, and roots of cabbage due to the fungus Phoma lingam. The plants are most susceptible in the seedling stage, but may be attacked at any time. Lesions are produced at the infected areas, and the small black pycnidia appear on the sunken tissues. Various Cruciferte are also liable to infection. Advice is given as to treatment both of the plants and of the infected soil. A. L. S. Rubber Disease. — A. Sharples {Ann. App. Biol., 1918, 4, 153-78, 6 pis.) publishes an account of disease due to Ustulina zonata, which was first known as a disease of tea and other plants, but which also attacks Hevea hrnsiUensis, and in Malaya is responsible for the death of many trees. The roots are chiefly attacked, and fructifications of the fungus are found at the collar. Holes made by boring insects are entered by the fungus, which spreads thence through the tissues. The writer recommends strict sanitation methods, clearing the ground of rotting timber, and the removal of old trees. A. L. S. Potato Leaf-roll.— E. J.Woin!hiiY'(Fhytopaiholof/y, 1918, 8, 507-29, 16 figs.) has made a study of the occurrence and history of this disease in Bermuda. After describing the effects produced on the potato plant he states that if the plants are carefully dug up the roots and stolons show darkened patches bearing on the surface the characteristic mycelium of Rhizoctonta. A long account is given of experiments in planting different kinds of potatoes. A. L. S. Diseases of Parsnip. — After describing a cracking disease of parsnip due to weather changes, A. D. Cotton (Keio Bull., 1918, 8-21, 2 pis., 2 figs.) has added a summary of diseases due to fungi : — Erysiplta Polyoni, Phyllachora Pastinacse, Ramularia Pastinacse, Cercosporella Pastmacse and Plasmopora nivea, all of which occur on the leaves and petioles of Pastinaca sativa. A. L. S. Rose-blotch Fungus. — N. L. Alcock {Kew Bull., 1918, 193-7, 1 pL, 2 figs.) gives an account of this fungus, which produces black blotches on the leaves in summer and autumn. The ascigerous stage has never been found in this country, but some years ago such a stage was discovered in America, and described under a new genus, Diplocarpon Wolff (Microthyriacese). The writer found conidial pustules on young twigs ; she suggests remedial measures, either spraying or removing all leaves and twigs that have been attacked. A. L. S. 'f •- Treatment of Scab in Potato Tubers. — G. II. Goo^fi {Phytopathology, 1918, 8, 457-68) records satisfactory results in the treatment of seed potatoes by sprinkling them with formaldehyde or by immersion in solutions of mercuric chloride. Without such treatment the crops raised from scattered tubers were poor and weak. Coons prefers the treatment with corrosive sublimate, 1 in 1000, for one half-hour. A. L. S. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 73 Blossom Wilt and Canker of Apple-trees. — This disease, due to Monilia, has been investigated by H. Wor]vl4.ld {Ann. App. Biol., 1917, 3, 159-204, 3 pis.). It has caused great loss to growers in the south- east of England. Infection takes place through the open flowers which are wilted ; the fungus then penetrates into the tissue of the flowering spur, which it kills ; it may also reach the branch and produce a canker. Monilia conidia are produced on these dead spurs during winter and spring, and reinfect the blossoms. The fungus is probably identical with M. cinerea Bon. It may be kept in check by cutting out the diseased spurs and cankers. A. L. S. "Wither Tip" of Plum-trees. — This disease is also due to J/omto, and an account of it has been published by H. Wormald {Ann. App. Biol., 1918, 5. 2H-59, 3 pis.). The fungus is morphologically similar to 31. cinerea, which causes "blossom wilt" of apple-trees, but must be considered as a " biologic form," as the results of infection are not the same. As with the above, Wormald advises the careful destruction of affected twigs, branches, etc. A. L. S. Disease due to Cytospora. — W. N. C. Belgrave {An7i. App. Biol., 19ir), 2, 183-94, lU figs.) has investigated the recurrence of this fungus on plum-trees in Cambridgeshire causing die-back. The first sign of disease is the withering of the leaves, usually progressing from the top of the trees downw^ards. The pycnidia appear in crater -like swellings of ,the bark. The spores were isolated and grown in pine cultures, pycnidia being successfully reproduced. The fungus is nearly related to, if not identical with, Cytospora leucostoma. No further stage was observed. Belgrave gives an account of the effect produced in the tissues by the fungus. A. L. S. ■■&' Disease of Carnations. — This has been investigated and described by P. A. VAN DER BiJL {Ann. App. Biol., 1916, 2, 267-91,4 pis.). It is known as "wilt" or " crow'n-rot," and is caused by a Fusarlum. Culture experiments were carried out successfully, and great attention is paid to means of combating the disease. A. L. S. Lichens. Lichenolog-y in Great Britain. — A. Lorrain Smith {Trans. Brit. Ml/col. Soc, 1918, 6, 32) publishes a statement intimating that the Mycological Society has decided to associate the study of Lichenology with that of Fungology. The Society invites lichenologists to become members, and so advance the study of lichens by collecting during the annual forays and by publishing papers on the subject. A. L. S. Monograph of British Lichens. — Part I. of the Catalogue of British Lichens has been rewritten by A. Lorrain Smith {British Museum {Natural History), 1918, xxiv and 520 pp., 71 pis. and figs.). It 74 SUMMARY OF CURKENT RESEARCHP:S RELATING TO is prefaced by an introduction giving a short account of the structure and biology of lichens. Orders, genera, and species have been re- arranged on modern lines. The changes in classfication and nomen- clature rendered necessary have been explained, and synoptic keys to orders and genera are provided. Large genera have been divided, and the species arranged in definite groups, which should simplify the study of lichen plants. A. L. S. New Lichen Genus.— Bruce Fink {Mycologia, 1918, 10, 235-8, 1 pi.) has placed in a new genus, Collemodes, the lichen examined by Freda M. Bachman as Collema puJposum. Bachman found in the lichen a new type of reproductive cells. The spermatia are budded from hyphge in the interior of the lichen tissue, and the trichogyne grows towards these groups of spermatia and fuses with one. The lichen is otherwise indistinguishable from Collema pulposwn, but it is not uncommon, and has been collected in several American States. The new species is published as Collemodes Bachmanianum. A. L. 8. Lichens of Sand-dunes. — W. Watson {Journ. EcoL, 1918, 6, 126-43), in his study of the cryptogamic vegetation of sand-dunes, has made a careful examination of the lichens. On somewhat loose sand- hills the lichens associated with Cyanophyceae, such as Peltigerse, Collemee, etc., are the chief types. Li more stable positions other and varied forms make their appearance, many of them with bright green gonidia. Trees are rare, but they carry a varied lichen-flora, not differ- ing, however, from the tree-lichens further inland. A. L. S. Bryophytes and Lichens of Calcareous Soil.— W. Watson {Journ. EcoL, 1918, 6, 189-98) indicates first the lichens that are distinctly calcifuge, then those that grow indifferently on any soil, or with a preference for calcareous substrata. He then gives lists of those found on calcareous walls, on chalk, on limestone grassland, limestone woods, and calcareous rocks, both shaded and exposed. A number of crustaceous calcicole lichens secrete an acid which forms pits in which the lichen fruits are sheltered. A. L. S. Notes on the Ecology of Lichens.— R. Paulson (Essex Naturalist, 1918, 19, 276-86, 3 pis.) has studied this subject in Epping Forest. He notes the greater abundance of lichens where oaks are dominant than where hornbeam is the principal tree. The latter casts a deeper shade, which inhibits the growth of most lichens. The nature of the soil, whether it be wet or dry, also influences the growth of lichens on the trees. Paulson also adds observations on the longevity and rate of growth of lichens. A. L. S. Lichens of a Boulder-clay Area.— The boulder-clay area worked by A. Mayfield {Ipswich and District Field Cluh, 1916, 5, 34-40) is situated in the centre o^ the county of Suffolk. He gives a general account of the lichen-flora of the various associations of trees in the district, with special attention to the kind of bark and of the ZOOLOGY AND BOTANY, MIUROSCOPY, ETC. 75 aspect. Terricolous species were few in number. " Only four plants, GoUema pulposiim, Cladonia pyxidata, C. furcata var. corymhosa, and Feltiyera polydactyla, attain proper development on hedgebanks and roadsides.'' A list of all the species found is appended. A. L. S. Mycetozoa. Shrewsbury Mycetozoa.— (I. Lister {Trans. Brit. Mycol. Soc, 1918, 6, 15-17) publishes a list, with occasional notes, of Mycetozoa collected at Shrewsbury during the annual fungus foray. The list numbers forty-seven species. A. L. S. Haunts of the Mycetozoa. — G. Lister (Essex Naturalist, 1918, 18, 301-21) has published her Presidential Address given to the Essex Field Club dealing with the above subject. She discusses these in order, and gives the characteristic Mycetozoa that occur in the different situ- ations. Such are woodlands with fallen timber, stumps and leaves, saw- dust heaps, spent tan, many different kinds of logs, trees, hedge-clippings, straw-heaps, manure, etc. The writer also gives an account of the species that specially favour Alpine pastures as well as various tropical habitats. Finallv a summary is given of species according to habitat. A. L. S. Mycetozoa in Britain. — G. Lister (Essex Naturalist, 1917-18, 18, 207-37) has issued, in her Presidential Address to the Essex Field Club, an account of the study of Mycetozoa in this country. The first record was made by John Ray in 1696, who describes a "certain small scarlet fungus," now known as Lycogala epidendrum. Further records were made by Dillenius, and later by Sir John Hill. Other authorities are quoted down to our own day. The latest scientific work on the group is carefully noted. (1. Lister then tabulates the species found in Epping Forest, numbering 82. She compares this list with'those of several other counties in Ensrland and Scotland. A. L. S. *&^ Mycetozoa of Chingford District. — Joseph Ross (Essex Naturalist, 1917, 18, 192-8) has published comparative lists of Mycetozoa for the above district in August and September, 1915 and 1916. Heavy rains in July, 1915, produced a fine crop of Mycetozoa, and some 35 species were listed. Dryer conditions in 1916 resulted in a less abundant growth, but a first record was made for Essex, Arcyria CErstedtii. A. L. S. 76 SUMMARY OF CUKKENT llESEARCHES RELATING TO MICROSCOPY. A. InstrumeSts, Accessories, etc. (3) Illuminating- and other Apparatus. The Light scattered by Gases : its Polarization and Intensity. R. J. Strutt {Proc. Roij. Soc, Series "A," 95). The present investi- 2:ation is a development in various directions of that described in the Proceedings of the Royal Society, "A," 94, 453, 1918. It is there shown that the light scattered by air and other gases in the direction perpendicular to the beam is almost completely polarized. It is of importance to determine whether or not the polarization of the scattered light at right angles to the beam is complete. Sky light is by no means completely polarized, but in that case the incident light is not all in one direction. The question is whether, apart from these compli-. cations, the polarization would be complete. This cannot be decided by observations on the sky, but the laboratory methods now described allow of this investigation, not only in the air, but in other gases also. The simple theory, according to which the polarization should be complete, assumes a spherical form for the molecules. That is to say, it is assumed that, however the molecule may be turned with reference to the direction of vibration in the primary beam, the result will be the same, and vibration induced will be wholly in that direction. Any departure from complete polarization would indicate that the molecule had certain preferential directions of vibration. The extreme case would be that in which the molecule could only vibrate in one direction fixed within it. The experimental arrangements for examining the polarization are the same as that described in a previous preliminary paper, except that slight modifications were introduced to enable the investigations to be made under the conditions specified. Since the effect to be looked forward for is small it is desirable to make the primary beam as intense as possible. An electric arc therefore was used with " Kinarko " kinematograpb carbons. These carbons give great intrinsic brightness. The horizontal core carbon charged with a special preparation was IS m.m. in diameter, presented end on to the condensing lens. The copper cord negative carbon, nearly vertical, was 10 m.m. in diameter. The current was about 25 amperes and the lamp was a hand -fed one. The varying intensities of the polarized beam were recorded by means of a photographic plate, so that reliance was not placed oil observational methods, but the result was determined by the differing capacities of the photographic deposit as shown by the resulting plate. The results obtained may be summarized as follows : — 1. The light scattered at right angles by gases and vapours is not completely polarized. The vibration parallel to the exerting beam has ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 77 ulready an appreciable intensity, which in ordinaiy cases varies from 1-2 p.c. in pentane to 14 p.c. in nitric-oxide of the intensity in a perpendicular direction. 2. Helium is an outstanding case, polarizing far less perfectly than any other gas. The measurements give an intensity in the parallel component nearly half as great as that which is in the perpendicular component. :^. Theory indicates that this is the ratio to be expected if the vibration in the helium atom is limited to a direction fixed within the atom, on the assumption, of course, of random orientation to the exciting light. Such an atom is the antithesis of the spherical atom or molecule which would give perfect polarization. 4. The intensity of scattering by the different gasses tried varies as the square of the refractivity within the limits of experimental error. 5. Saturated vapours, even when very dense, show no increase of scattering power beyond what the density would lead one to expect. If molecular aggregates are formed they are not numerous enough to show by this metliod. G. Liquid ether apparently scatters about six times less light than the corresponding mass of ether vapour. J. E. B. C5) Microscopical Optics and Manipulation. National Physical Laboratory Report for the year 1917-1918. — That portion of the report dealing with Optical Glass Testing is of interest to microscopists. The number of specimens of glass experimented with has risen largely during the past year. The Auxiliary Apparatus used in connexion with these tests, which was mentioned in the last report and was shown at the Optical Society's Exhibition held in January, 1917, has continued to give the greatest satisfaction. The tests are made on a Pulfrich Refractometer, and experience shows that a properly constructed instrument of this type, used under suitable conditions, gives entirely reliable and accurate results. During the past year investigations of a comprehensive character, both experi- mental and theoretical, have been made on various aspects of Rt-fracto- metry and on the types of instruments suitable for high accuracy in such measurements. As a result proposals for a new form of instru- ment have been made, but this unfortunately cannot be obtained during the War. There have been several requests during the past year for the examination for optical properties of specimens of glass wliich were not specially prepared for that examination. Presumably this refers to the testing of pieces of glass which have neither of their surfaces polished, and which, therefore, cannot be tested by the Refractometer metliod. The tests in these cases are carried out by an immersion method. The accuracy obtainable varies with different specimens, but it has proved sufficient in all cases to enable the particular glass employed to be identified. The accuracy is, of course, less than that which is secured when suitably prepared specimens are tested. J. E. B. VS SUMMARY OF CURRENT RESEARCHES RELATING TO [B. Technique. (3) Cutting', including- Embedding and Microtomes. Modification of Hand Microtome. — T. H. Goodspeed {Botanical Gazette, 1918, 66, No. (5, 534-6, 5 figs.). Figs. 1-5 represent a simple modification of the familiar hand microtome, and the author has found it to be a decided improvement over the original instrument from which it was derived. In the ordinary type, when cutting sections of woody stems or more delicate material held in pith, it is always difficult to be certain of obtaining the necessary pressure for holding the material at the proper point. The steel rod which moves in or out upon the turning of the single pressure screw will usually hold the material firmly at its lower end, but not so firmly at its upper end, with the result that the material has a tendency to wobble when the knife begins to cut the section. On the other hand, when this difficulty does not arise it is often almost impossible to screw up the material for the next section because of the pressure of the material against the walls of the tube or well. To obviate these rather commonly encountered difficulties in the ordinary type of hand microtome the modification of it shown in the figures has been devised. Figs. 4 and 5 give two views of an inner " material holder." It consists of two pieces of curved steel which are long enough to reach to the bottom of the tube or well (just below cc in fig. 2). This inner material holder is provided with a spreading spring at ed which surrounds a small steel bar cc. Each curved piece of steel has a hole at aa (fig. 4) through which project the ends of the two pressure screws hh (fig. 2). The manipalation of the apparatus is as follows where, for example, cross-sections of a woody stem are to be cut. The pressure screws hh are turned out lantil their ends at aa are pulled out of the holes in the material holder. The microtome is inverted and the material holder falls out. The stem or a portion of it is placed between the leaves of the material holder and properly oriented, and if necessary a rubber band is bound around the material holder just above aa. The material holder, containing the stem, is now pushed down into the well or tube of the microtome and oriented so that the holes are opposite the ends aa of the turned-back pressure screws. These screws are turned in, their ends pass into the holes in the material holder, and pressure is finally exerted on both sides. As the pressure becomes greater, the spring at dc prevents the upper ends of the material holder from spreading, and ensures maximum pressure against the material at these upper ends. Finally, the stem is held firmly in the centre of the tube or well of the microtome between the leaves of the material holder. The pressure screws are free to move up or down in their openings because no appreciable pressure is exerted upon the walls of the tube or well. In a similar manner material held in pith is very conveniently arranged in this apparatus. The possibility of arranging and orienting such material held in pith in the material holder outside the microtome ZOOLOGY AND BOTANY, MICllOSCOPY, ETC. 79 80, SUMMARY OF CURRENT RESEARCHE« RELATING TO is an obvious advantage. Longitudinal sections of small woody stems are readily cut in this modified hand microtome, whereas their small diameter makes it very difficult to secure them firmly in the original apparatus. As may be seen, it is possible to orient material to obtain all angles in the case of sections to be cut obliquely or in the case of unsymmetrical material. The original modification from which the drawing was made has been somewhat improved recently. The knurled heads hh should be much larger than those illustrated, and for woody stems the leaves of the material holder should be thicker and their inner surfaces more nearly flat. A. N. D. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 81 METALLOGRAPHY, Etc. Decomposition of Metals. — Colonel A. I. Krynitzky {Chemical and Metallurgical Engineering, 20, No. 6, March 1919). A critical review of various theories which have been advanced from time to time to explain the so-called " Disease of Metal." Allotropy, recrystalliza- tion, corrosion, and season cracking may each be responsible for some types of such failures. Etching- Media commonly used in Non-ferrous Metallography. — J. Smout {The Metal Industry, 1918, 14, No. 1). A few of the difiPerent classes of etching. Describes etching media used for copper, brass, bronze, nickel, G-erman silver. Rapid Recrystallization in Deformed Non-ferrous Metals. — D. Hanson {The 3Ietal Imlustry, 1918, 13, 183) describes recrystalliza- tion phenomena of aluminium, magnesium, zinc, lead, copper and certain alloys of the same. The Metallography of Aluminium.— Robert J. Anderson {The 3Ietal Industry, 14, No. 1;!, March 1919). Exaggerated growth in aluminium. Silver bands in aluminium. Polishing and etching aluminium. The Micrography of Aluminium and its Alloys. — D. Hanson and S. L. Archbutt {The Metal Industry, 14, No. 14, April 4, 1919). Preparation of sections. The micrographic constituents of aluminium alloys. Pure aluminium. Copper-aluminium alloys. Zinc-aluminium alloys, magnesium-aluminium alloys, manganese-aluminium alloys. A Few of some of the Mechanical Properties of the Alloys of Copper and Zinc— F. Johnson {The Metal Industry, 13, 188-190) describes certain tests made by members of the Metallurgy Department of the Birmingham Technical School, showing relations between Brinell hardness, scleroscope hardness, tensile tests, microscopic examination and analytical examination of parts as cast and after annealing. The Properties of some Copper Alloys. — AV. Rosenhain, B.A., and D. Hanson {The Metal Industry, 14, No. 14, April 14. 1919). Alloys of copper with aluminium, with manganese and aluminium, not containing zinc. Alloys free from aluminium. Effect of Heat Treatment on Bronze. — F. F. Hausen and 0. A. Knight {The Iron Age, 1919. 103, No. (i, 347). Characteristics dis- closed by Brinell hardness tests and photomicrographs. Quenching and drawing give greater hardness than quenching alone. 82 SUMMARY OF CUKRENT RESEARCHES, Flakes in Alloy Steel. — Howe, Clayton, Rawdon, Foley, and Laney {IVie Chemical and Metallurgical Engineering^ 1919, 20, No. 5, 216). An outline of papers and discussion of this important defect presented at the New York meeting of the American Institute of Mining Engineers. G-rain Limits in Heat-treated Alloy Steels. — R. S. Archer {The Iron Age, 1919, 103, No. 6, 366). New etching process which defines the crystals, boundaries, and assists in detecting faulty heat treatment. New Light on Transverse Fissures.— G. F. Comstock {The Iron Age, 1919, 103, No. 10, 613). Phosphorus streaks as a cause of such rail defects. How they form and what they are. Effects of reheating the blooms. Static, Dynamic and Notch Toughness.— Samuel L, Hott {The Iron Age, 1919, 103, No. 9, 545). Value of the Charpy test in deter- mining ability of steel to resist rupture under notch conditions. Its use in Europe. The Metallography of Heat Treatment of Metals used in Aeroplane Construction. II. — F. Grotts [Chemical and Metallurgical Engineering, 1918, 19, 191-196). Investigation of parts made from medium-carbon, high-carbon and chrome-nickel steels. Causes of failure in cam wheels, piston pins and crank shafts. 83 PEOCEEDINGS OF THE SOCIETY. AN ORDINARY MEETING OF THE Society was held at 20 Hanover Square, AY., on Wednesday, December 18th, 1918, at 5.30 p.m., Mr. J. E. Barnard, President, in the Chair. The Minutes of the last Meeting were read, confirmed, and signed by the President. Mr. Herbert George Blackmore was duly elected a Fellow of the Society. The following Exhibits were made, and votes of thanks passed to the Exhibitors : — Mr. Earland : — A slide of Cretaceous Forarainifera from Chalk Marl, taken from a shell crater at Noyelles-sur-Escaut, just inside the Hindenburg Line, sent by Mr. Heron-Allen. Mr. E. J. Sheppard: — Slides showing sections of Testes of Hermaphro- dite Goat, sent by Mr. Basil Adams. Mr. Scourfield : — Eye-piece Micrometer, by J. Rheinberg, with eccentric scale. Col. Castellani read a paper on " Tropical Diseases met with in the Balkanic War Zone." The paper was illustrated by microscopical slides showing Oidium asteroides, 0. matalense, 0. rotundatum, Monilia balcanica, Accladium Cast, and Pinnoy, 1916, Fungus, sp. 48, Hemisphora rugosa (Bronch.), TokeJau, and Tinea imbricata, and also by a number of lantern -slides. The paper will appear in the pages of the Journal. Dr. Eyre, in moving a very hearty vote of thanks to Col. Castellani for his most interesting paper, which helped to show the valuable place filled by the microscope under war conditions, said that a few years ago the use of the microscope and laboratory methods were looked at askance by the older school, and it had taken a European War to bring home not only to the man in the street but also to the medical practitioner the immense advantages that could be derived from the use of the micro- scope. The experiments of Col. Castellani had helped to win the War, and in bringing them to the notice of the Society he had opened up a G 2 84 PEOCEEPINGS OF THE SOCIETY. still wider field. He had touched upon the parasitic fungi. Some of the cultures were quite new, and when there had been time to sort out the immense amount of material that had been collected, he hoped that Col. Castellani would be able to come and give the Society the result of his investigations in microscopical fungi. Mr. Earland seconded the vote of thanks, which was carried by acclamation. The following papers by Dr. Hartridge were read :— " An Improved Method of Apertometry " ; "A Method of Adjusting Tube-Length " ; " Eye-pieces with Adjustable Compensation." A hearty vote of thanks was accorded to Dr. Hartridge for these pap(irs, which will appear in the pages of the Journal. It was announced that the next Meeting would be held on January 15th, and that of the Biological Section on January 8th, when Mr. Scourfield would make a communication on " The Sense Organs of Daphnia and its Allies." 'to" AN ORDINAEY MEETING OF THE Society was held at 20 Hanovee Squaee, W.. on Wednesday, Januaey 15th, 1919, Mr. A. Eaeland, Vice- Peesident, in the Chaie. The Minutes of the preceding Meeting were read, confirmed, and signed by the Chairman. The nomination papers were read of the following Candidates for Fellowship : — Mr. Ahmed Zahy Abushady, L.M.S.S.A. Mr. Ernest Henry Grant. The Annual Report of the Council for 1918 was read as follows : — fellows. During the year 33 Ordinary Fellows have been elected, 10 have died, and 15 have resigned or have been removed from the Roll. One Honorary Fellow has been. elected. The names of 7 Honorary Fellows PROCEEDIISIGS OF THE SOCIETY. 85 and 12 Ex-officio Fellows have been removed from the Roll. The number of Fellows at the end of the year 1918 was as follows : — Ordinary . 387 Honorary 20 Ex-officio G9 Corresponding 1 477 Of the Ordinary Fellows — 305 have paid the annual subscription. 37 have compounded. 13 have had subscriptions remitted. 32 remained unpaid (of these three have since paid). 387 The deaths referred to above included those of Dr. Hebb, for many years Secretary of the Society and Editor of its Journal, and Professor H. G. Plimmer, who was President of the Society for the years 1911 and 1912. FINANCE. The Financial Statement will be presented at a subsequent Meeting. JOURNAL. The death in May last of Dr. Hebb, the Editor of the Journal, was a very serious loss to the Society, and this, coupled with the difficulties connected with the supply of paper and the increased cost of printing, caused your Council great anxiety. Dr. Singer very kindly offered his services as Honorary Editor, and they were gladly accepted, together with offers of assistance from other Members of the Council. It is hoped in the near future, when more normal conditions return, that the Journal may be developed and exercise a wider influence in all branches of microscopical science. The Council wishes to take this opportunity to thank most cordially the Contributors and Abstractors for their valuable work during the past year. LIBRAEY. The Library has been utilized by a considerable number of Fellows, and the number of books borrowed from Lewis's Library has been larger than usual. During the year an innovation has been made by arranging for the rooms of the Society to remain open on Wednesday evenings (other than meeting evenings) from six to nine o'clock, in order to afford greater facilities for the use of the Library. G 3 86 PROCEEDINGS OF THE SOCIETY. INSTRUMENTS AND APPARATUS. The Instruments and Apparatus are in excellent condition. During the year the Society has received the following donations: — Lady Flower : — An old Microscope, by Hugh Powell, with accessories. Mrs. Hebb : — Microscope, by Baker, with Polariscope and other accessories, which had been in constant use by the late Dr. Hebb. Mr. J. Rheinberg : — A Set of Photographic Scales and Micrometer Rulings. In connexion with the British Science Guilds' Exhibition of Scientific Products at King's College, the Society exhibited a number of instruments to illustrate the Evolution of the British Microscope, and a special report on this subject appears in the Journal. CABINET. During the year the Slides Cabinet has been thoroughly overhauled and reclassified, and a full report has been presented, which has appeared in the Journal. The Council has expressed its appreciation of the enthusiastic exertions of the Sub-Committee, consisting of Mr. A. Earland and Mr. E. J. Sheppard, which has undertaken this work so successfully, and trusts that the Fellows of the Society will now co-operate in providing slides for those sections which are at present inadequately represented. The Cabinet will be available for the use of Fellows in the course of a few months, on the completion of the Card Index. During the year the Council has received from Dr. Urban Pritchard a valuable addition to the Cabinet, in the shape of 100 special Diatom Slides. The Wallich Collection, consisting of 995 Diatom and other Slides, together with a series of descriptive note-books and drawings illustrating the Collection, has been presented by the Society to the Trustees of the British Museum. MEETINGS. Notwithstanding the abnormal conditions under which the work of the Society has been carried on, the meetings have been held as usual, the attendance of Fellows and Visitors has been maintained, and the papers read have been well up to the high standard set by the Society. The Biological Section, which meets on the first Wednesday of each month, has had a most successful programme of events, which has included special visits to the liondon School of Medicine for Women ; the John Innes Horticultural Institute, Merton ; King's College Laboratories. The thanks of the Society are due to Mr. J. Wilson for his continued energy and activity as Honorary Secretary of this Section. PEOCEEDINGS OF THE SOCIETY. 87 Mr. Mortimer moved, and Mr. E. J. Sheppard seconded, that the Annual Report be received and adopted. Carried. Mr. Henson moved, and Mr. W. Watson Baker seconded, that a very hearty vote of thanks be tendered to the Honorary Officers and Members of the Council for their services to the Society during the past year. Carried. The Chairman appointed Mr. D. Davies and Mr. W. Watson Baker to act as Scrutineers, and afterwards announced the result of the ballot for the election of Officers and Council for the ensuing year as follows : — President. — Joseph E. Barnard. Vice-Presidents.— 'EiA.viQx^ Heron-Allen, F.L.S., F.Z.S., F.G.S., M.R.I.A., etc. ; Alfred N. Disney, M.A., B.Sc. ; F. Martin Duncan, F.R.P.S. ; Robert Paulson, F.L.S. Treasurer. — Cyril F. Hill. Secretaries.— S . W. H. Eyre, M.D., M.S., F.R.S. Edin. ; David J. Scourfield, F.Z.S. Council. — Herbert F. Angus ; Maurice Blood, M.A., F.C.S. ; Frederick J. Cheshire, C.B.E. ; T. H. Hiscott ; Benj. Moore, M.A., D.Sc, F.R.S. ; Percy E. Radley ; A. W. Sheppard ; Edward J. Sheppard ; Charles Singer, M.A., M.D. ; Joseph Wilson ; G. Sims Woodhead, M.A., M.D., LL.D., etc. ; B. B. Woodward, F.L.S., F.G.S. Librarian. — Percy E. Radley. Curators. — Edward J. Sheppard ; Charles Singer, M.A,, M.D. A vote of thanks to the Scrutineers was moved from the Chair and carried. The Chairman announced that owing to the illness of the President it would be necessary to postpone the Presidential Address until the next Meeting. As the news had only reached them that morning, it was too late to send out notices or arrange for other papers. Mr. Scourfield had however kindly stepped into the gap, and had promised to give them a communication on " The Sense-organs of DapJmia and its Allies." ► The Chairman exhibited a slide of a Schizopod, Hoplophragmium canariense (d'Orbigny), at the request of Mr. J. Hopkinson. Votes of thanks were duly accorded to Mr. Scourfield and the Chairman. The Chairman announced that the next Meeting would be held on February 19, and that the Biological Section would meet on February 5, when Mr. A. W. Sheppard would make a communication on " The Pollen Chamber of Cycads and its Function." The business proceedings then terminated. 88 PEOCEEDINGS OF THE SOCIETY. AN ORDINARY MEETING OF THfc Society was Held at 20 Hanover Square, W., on Wednesj)Ay, February 19th, 1919, Mr. J. E. Barnard, President, in the Chair. The Minutes of the preceding Meeting were read, confirmed, and signed by the President. The Nomination Papers were read of the following candidates for Fellowship : — Capt. Raymond S. Harper, M.R.C.S., L.R.C.P. Rev. A. F. Gordon Mackay. Mr. Albert Taylor. New Fellows.— The following were elected Ordinary Fellows of the Society : — Mr. Ahmed Zaky Abushady, L.M.S.S.A. Mr. Ernest Henry Grant. Donations to the Society were reported from : — The Department of Scientific and Industrial Research- " The Theory of Modern Optical Instruments." The Macmillan Company — " Mirrors, Prisms and Lenses." The thanks of the Society were accorded to the donors. An Exhibit of Stains, Reagents, and Mounting Media for Micro- scopical Purposes, and Indicators used in Bacteriology and Volumetric Analysis, manufactured by the British Drug Houses, Ltd., was shown by their representative, Mr. Thomas Tusting Cocking, F.I.C. The exhibit was arranged for the purpose of bringing to the notice of Fellows of the Royal Microscopical Society, dyes, stains, and other microscopical requisites, of guaranteed purity and of British manufac- ture, so that microscopists could rely upon obtaining British preparations- of uniform purity to replace the pre-war German products. Specimens of the following were exhibited, showing that much has already been accomplished in this direction, and it was confidently anticipated that the experiments that were being made would result in PROCEEDINGS OF THE SOCIETY. 89 a considerable extension of the number of microscopical requisites now available. Dry Stains. Axur I. (methylene azure). Azur II. Azur II. eosin. Ammonia carmine. Di-chloro-fluorescein. Di-chloro-di-bromo-fluorescein. Di-chloro-di-iodo-fluorescein . Di-bromo-di-iodo-fluorescein. Eosin yellow shade (tetra-bromo- fluorescein). Eosin methylene blue. Eosin orange (di-bromo-fluorescein). Erythrosin A (tri-iodo-iiuorescein). Erythrosin B (tetra-iodo-fluorescein). Erythrosin G (di-iodo-fluorescein). Fluorescein. Fluorescein sodium (soluble in water). Gienasa's stain. Haematein. Jenner's stain. Lithia carmine. Methylene blue polychrome. Methylene violet. Picro-carmine lithia. Picro-carmine soda. Tetra-chloro-fluorescein. Tri-bromo-fluorescein. Tri-chloro-fiuorescein. A colour-chart of fluorescein and its halogen derivatives was exhibited. It had been prepared from equimolecular solutions of the dyes, and showed that each increase in the molecular weight was accompanied by an increase in the depth, and also a change in the colour of the dye. Staining Solutions and Reagents. Alum cochineal. Carbol fuchsin. Carbol methylene blue. Carmine : — Beale's ammonia carmine. Grenacher's alum carmine. ,, borax carmine. ,, alcoholic borax carmine. Mayer's borax carmine. Orth's lithia carmine. Carmalum (Mayer). Edington's hsemacytometer solution. Ehrlich's triacid stain. ,, triple stain. Eosin 2 p.c. Erythrosin 0'5 p.c. Gentian violet (aniline water). Gram's iodine. Gibbe's double stain. Giemsa's stain. Hsemalum (Mayer). Haematoxylin : — Delafield's htematoxylin. Ehrlich's hsematoxylin. ,, ammoniated hsematoxylin Kleinberg's hgematoxylin. Bohmer's hsematoxylin. Jenner's stain. Leishman's stain. LSffler's stain. Malachite green. Methyl violet (aniline water). Phloroglucin. Picro-aniline blue. Picro-carmine ammonia. Picro-carmine lithia. Picro-fuchsin. Schultze's solution. Toison's solution. , Mounting Media. Alpha-bromonaphthalene. Cedar-wood oil. Canada balsam in benzene. Canada balsam in xylene. Dammar varnish. Dammar and mastic. Glycerin jelly. Indicatohs in Solution and Solid Form. Azolitmin. Bromo-phenol-blue (tetra-bromo- phenol-sulphone-phthalein). Di-methyl-amido-azo-benzene. lodo-eosin (tetra-iod o-fluorescein) . Lacmoid. Methyl red. Phenol red (phenol - sulphone - phthalein). Phenacetolin. Thymol blue (thymol-sulphone- phthalein). Thymol phthalein. 90 PROCEEDINGS OF THE SOCIETY. In proposing a vote of thanks to Mr. Cocking for his exhibit, the President said he did not claim any special knowledge of the action of dyes when employed in microscopical preparations. The necessary tests must be made by those who were accustomed to that class of work. It did not by any means follow that the purest dyes were the most efficient. It was not so much a question of producing the purest dye as of finding a dye, even if it contained a particular impurity, that was most suitable for microscopical work. The vote of thanks was carried unanimously. Mr. H. Taverner exhil^ited Photomicrographs of Water Mites by the Sangster-Sheppard process. Mr. Taverner was heartily thanked for his exhibit. The President then delivered his Presidential Address, entitled " The Limitations of Microscopy." Prof. Cheshire moved : " That the best thanks of this meeting be accorded to Mr. Barnard for his Presidential Address, and that he be asked to allow it to be printed in the Journal of the Society." Lieut. -Col. Clibborn seconded the proposal, which was supported by Dr. J. Rudd Leeson, and carried by acclamation. The President thanked the meeting, and said he would regard it as an honour to have the address printed in the Journal. The President announced that the next meeting of the Society would be held on March 19, and of the Biological Section on March 5, when Mr. F. Martin Duncan would make^a communication, " Notes on some Marine Crustacea." JOURNAL OF THE EOYAL MICEOSCOPICAL SOCIETY. JUNE, 1919. TEANSACTIONS OF THE SOCIETY. I III. — The Identification of Intracellular Structures. By J. Bronte Gatenby, Senior Demy, Magdalen College, Oxford, Lecturer in Cytology, University College, London. With Fourteen Text-Fiqures. Introductory, The object of these notes is to put before zoologists, and to some extent botanists too, certain results in practical histo-chemistry, from the cytologists' point of view. I shall make no attempt to add anything to physiological chemistry, but rather to classify the organs of the cell under their proper heads. Such modern and valuable works as the "Monographs on Biochemistry," by Plimmer, Leathes, Maclean and others, are written from a different point of view from that generally taken by zoologists, and in the present paper I have tried to unite some of the results of biochemistry with those of cytology. The physiological or bio-chemist writes of his reagents as they affect any given organic substance ; the working cytologist regards his fixing reagents, not altogether as they themselves affect the cell or any of its bodies, but as to the state in which cells appear after the fixed material has been treated in up-graded alcohols and a clearing oil. Most biochemists, on the other hand, working on materials extracted in bulk, often after desiccation or by destruc- tive extraction by liquids, lose sight of the view of the worker who deals with individual cell organs.-? -~==^ ' H 94 Transactions of the Society. A Tentative Classification of Cell Elements. In the animal cell, be it a spleen, germ, nerve-cell or other such structure, the cytologist may meet the following fairly sharply marked bodies : Nucleus and cytoplasm, and in the latter, fat, yolk, pigment, glycogen, mitochondria and Golgi apparatus. My own researches have led me to classify the mitochondria and Golgi apparatus (fig. 1) as the Protoplasmic (or living) Inclusions, and the fat, yolk, glycogen and pigment as well as such bodies as zymogen granules, as Deutoplasmic (Metaplasmic, dead) Inclusions. This classification is given below, and I should mention that it is entirely practical and pays no attention to the theoretical side of the question. While the somewhat arbitrary classes Protoplasmic (living) and Deutoplasmic (dead) may be artificial, and undoubtedly are constantly being bridged by transitional substances, this system has been temporarily adopted, and it merely remains to be seen how far it will stand criticism of other workers. Nucleus. Cell Cytoplasm Centrosome. /I. Protoplasmiclnclusions (Living) : — (a) Mitochondria. (b) Golgi apparatus. (c) Possibly other less numerous enigmatic protoplasmic granules (17).* 2. Deutoplasmic Inclusions (Dead). (a) Yolk. {b) Fat or oil. (c) Glycogen or starch. (d) Pigment when not united with mito- chondria. 3. Ground cytoplasm or protoplasm (Living). In many animal cells one finds in addition zymogen, oxyphile or basophile, and other (metaplasmic ? ) elements not mentioned under the Deutoplasmic Inclusions. In all the cases of which I know, these elements are secondary formations derived from various sources in the differentiation of the cell. Thus the granules in different sorts of leucocytes are developed during the differentia- tion of the cell. The embryonic and indifferent cell does not contain such derivatives, and it is to be understood that the above classification does not particularly deal with all the many enigmatic metaplasmic or deutoplasmic granulations which one meets quite often in the differentiated somatic cells. It is also quite likely (though still disputed) that mitochondria change into zymogen granules and fat; Guilliermond shoM's that this applies to plant starch, though we do not know so much about glycogen ; there would hence be a transition between the cytoplasmic living inclu- sions and the metaplasmic inclusions. This must be taken into * The italic figures within brackets refer to the Bibliography at end of the paper. Thf. Identification of Intracellular Structures. 95 account in the reading of the above classification. The key to the difficulty lies in differentiation ; possibly all embryonic cells would fall under the above classification. One of the greatest difficulties is to ascertain whether the given cell granule is a living plastid- like body, or merely a dead granule, and many of the so-called oxyphile and basophile granules have only been studied in alcohol and acetic acid fixatives, which give deceptive and entirely useless results from this present point of view (Leishman and Jenner). The Mitochondeia and Golgi Apparatus in Stained Sections. The mitochondria and Golgi apparatus (figs. 1-3) never clearly appear in stained sections prepared by such methods as fixation in corrosive acetic, Gilson, picro-nitric, Bouin, Carnoy or Flemming- with-acetic acid, and staining in Ehrlich's hsematoxylin and eosin, toluidin-blue and eosin, paracarmine and borax carmine. Though the mitochondria and Golgi apparatus are properly fixed by formalin, Miiller, Flemming-without-acetic acid, Champy, Altmann, etc., they will rarely appear visible in stained sections which have been pre- pared in Ehrlich's hsematoxylin or carmine stains, or in fact in any of the current laboratory stains used for general zoological purposes. The mitochondria and Golgi apparatus may appear visible in sections fixed in formalin, Miiller, etc., and stained in Altmann's acid fuchsin-picric acid, iron-hsematoxylin, Benda's alizarin and crystal- violet, etc. The Golgi apparatus rarely becomes visible after any of the above methods, and to study it one must use more specialized methods ; to study the Golgi apparatus and the mitochondria by routine zoological laboratory technique is not possible, simply because these methods will not demonstrate the bodies in question. The Golgi apparatus was first discovered by the Italian worker after whom it is named, and was independently observed by Cajal. Both Golgi and Cajal and their pupils worked principally upon the "apparato reticolare interne," or Golgi apparatus of the nerve ganglion cells of vertebrates. They used exclusively silver nitrate or metallic impregnation methods. The Golgi apparatus of nerve-cells has been studied exhaustively by workers in every country, and new technical improvements have enabled observers to use the Golgi and Cajal silver methods with fairly uniform success. Besides these few silver methods for demonstrating the Golgi apparatus in nerve-cells, Kopsch (5) has perfected an osmic acid method which shows precisely the same structures by a shorter and easier method (see below). Within the last few years Weigl iil), Hirschler(5, '20), Pappenheimer (it*), Sjdvall {26), and myself {17) and others have applied the silver and osmic methods, or H 2 96 Transactions of the Society. modifications of them, to every category of glandular and sex-cell in the body of a large number of animals, with the surprising result that it has been established that every animal cell so far studied carefully has been found to possess a more or less typical " apparato interno" of Golgi. Figures of cells showing the typical Golgi apparatus have been given in another paper {17). Certain observers have urged that the Golgi apparatus is only another form 7 mr ■^- HIT. „^^ ' of the mitochondria or chondriokonts ; such workers are few, and belong to a small body of cy tologists who specialize in one method, and who persist in raising objections without trying other and new methods. The methods of Benda and Haidenhain rarely demon- strate the Golgi apparatus, and unless the techniques of Golgi or Cajal, and Kopsch or Sjovall are used it is impossible in most cases to find the " apparato." The Identification of Intracellular Structures. 97 In nearly all cells, and certainly during some period in the life of the cell, the Golgi apparatus lies in the juxta-nuclear position drawn in fig. 1, The apparatus here consists of batonettes or little rods stuck upon the surface of the archoplasm or attraction sphere. Inside the archoplasm lies the centrosome or centrosomes. In highly differentiated cells, such as the nerve ganglion cell or the egg, and in the only protozoan in which the apparatus has been studied {Monocystis ascidiie, 20), it is found generally that the batonettes or grains leave their juxta-nuclear position and pass outwards and become spread out in the cytoplasm {6, 10, 17) (fig. 13). It has now been established by Hii'schler, Weigl and myself (6", 17, 21) that the Golgi granules (like the mitochondria) are able to divide independently of the other elements in the cell ; both the Golgi elements and the mitochondria are living proto- plasmic organs possessing the power of increasing rapidly in number by binary, and in the case of the Golgi elements occasion- ally (6") by multiple fission. In another section of this paper more <3 J o^u c Explanation op Text-figs. 1-3. (Not to scale.) Text-fig 1. — Cell fixed in chrome osmium and stained in Altmann or Benda, except that the glycogen is added to the figure. At NUC is the nucleus ; PLAS, plasmosome ; KARY, karyosome. At GOLGI is the Golgi apparatus, the separate elements or batonettes (dictyosome, etc.) black. At FAT is a fat globule gone black with osmium tetroxide. At GLY is the irregular glycogen mass (absolute alcohol and Best's carmine, or iodine). At MIT are the small regular mitochondria (some- times rod-shaped, fig. 2a). At YOLK are early yolk discs, staining yellowish-green in the osmic acid. At VAC, X, is a vacuole with a small coagulum inside ; this may be either a fatty vacuole, or a watery, partiaUy proteid one. At VAC is a vacuole whose contents have entirely gone. This would be a pure liquid one, not contain- ing fat or coagulable proteid. Text-fig 2. — Difierent kinds of mitochondrial elements (Mitochondria). A, long chondriokont {kovtos, a pole). B, other kinds of elongate mitochondria or chon- driokonts. C, granular mitochondria or chondriosomes. Text-fig 3. — Various kinds of Golgi elements. D, upper shows a dittosome or batonette lying upon an archoplasmic mass ; lower shows three batonettes clear of latter. Note shape. E, other forms of multiple batonettes and archoplasm. F, irregular grains foimd during cell division after elements separate, preparatory to sorting out between daughter-cells. G, Golgi elements in form of reticulum (juxta-nuclear). H, branched elements free in cytoplasm, after breaking up of reticulum. D, E, G are constant forms. 98 Transactions of the Society. has been said about the morphology of the Golgi elements and mitochondria. The latter are so well known that it is unnecessary at this juncture to do more than mention that they are granular, Explanation of Text-figs 4-7. Illustrating Karyokinesis, Dictyokinesis, and Chondrokinesis. (Diagrammatic.) Letters. — C = centrosome and archoplasmic sphere. CS = chromatin spireme. CH = chromosomes. G = Gclgi rod (nebenkern batonette, dictyosome, chrondrio- plast). K = karyosome. L := linin of nucleus. M = mitochondrium. PL = plasmosome. Fig. 4.— "Besting" cell. Fig. 5. — Prophase ; centrosome divided, spindle-forming ; archoplasmic sphere disappearing; Golgi rods becoming sorted out into two subequal parts (six and seven) ; chromatinic spireme in nucleus, and mitochondria inert. Fig. 6. — Nuclear membrane disappearing, karyosome and plasmosome floating free preparatory to degeneration, chromosomes present, and Golgi rods at asters of spindle. Fig, 7. — Metaphase and splitting of chromosomes, karyosome disappearing. The Identification of Intracelhdar Structures. 99 filamentous or rod-like, generally very numerous elements, strewn through the cytoplasm of cells, and that they have been found in all plant and animal cells carefully studied by experts. There may be rare exceptions where no mitochondria are present, but this is due to the fact that differentiation has for some unknown reason caused the presence of mitochondria to be unnecessary ; one such case as this is the duct-cells of the rabbit's liver, and of several other glands in vertebrates. Karyokinesis, Dictyokinesis and Chondkokinesis. Certain Italian workers {12, 33) have referred to the Golgi rod or batonette as a " dictyosome," and Perroncito has suggested that the process of the sorting out of the " dictyosomes " or rods between the daughter-cells during cell-division should be called " dictyo- kinesis." In my previous papers I have entered into the question of dictyokinesis in Pulmonate Mollusca(i7) and Lepidoptera (17). In figs. 4-14 I have drawn diagram matically the process of dictyo- kinesis ; these figures would apply to all the known examples and varieties of dictyokinesis. In fig. 4 the rods G lie upon the sphere or archoplasm c ; the centrosome divides and the arrange- ment of the (thirteen) rods becomes altered ; each centrosome attracts to it about half of the whole rods as in fig. 5 ; the left aster has seven of the rods, the right only six ; in fig. 6 this is more easily seen. The rods keep around the amphiastral figure. In figs. 7, 8, 9 and 10 subsequent stages are shown. In figs. 9 and 10 the sphere or archoplasm is reforming, after its dissolution in fig. 5. In cell-division the mitochondria are also distributed between the two daughter-cells ; like the Golgi elements, and unlike the chromosomes, they are only sorted out haphazardly between the new cells. This sorting-out process has been called chondrokinesis, taking the part x^vSpo'i (a grain) of the words " mitochondrium chondriokont or chondriosome," and the word " kinesis." Examina- tion of figs. 4-10 shows that the mitochondria lie inert in the cytoplasm and are passively distributed between the daughter- cells. In these descriptions of dictyokinesis and chondrokinesis I have made no mention of the fact that some staining change comes over both chondriokonts or mitochondria and Golgi rods or granules during the process of cell-division (17). With reference to karo- kinesis, or the division of the nucleus, it is hardly necessary to explain figs. 4-10, as the process has been described in text-books such as that of Wilson on the " Cell." In figs. 6 and 7 the plasmo- some and karyosome are seen to degenerate and to become reformed in fig. 10. 100 Transactions of the Society. The process of dictyokinesis has been described in the follow- ing : — Cells of Descemet's membrane of mammalian eye (Deinecka, ^S) ; eight species of Pulmonate Mollusca* (Gatenby, 17) ; thyroid gland cells of mammals (Cajal, 10) ; Paludina (Perroncito and Gatenby, 17 and 22) ; Lepidoptera (Gatenby, 17), Argas (Casteel, 24). I have also observed dictyokinesis in many somatic cells of Triton and Eana, but my results have not yet been published, and are much like those of Cajal on the thyroid gland. In fig, 14 is drawn a type of dictyokinesis in which the Golgi reticulum has broken into more or less irregular granules, which keep around the zone of the amphiaster, but not necessarily around the asters ; this type is common in vertebrate gland cells. In figs. 11-14 rare cases of chondrokinesis or dictyokinesis are given. Fig. 11 is that of the typic spermatocyte of Paludina vivipara, where the mitochondria are few and large and have become constricted in the middle so that each cell gets one half of the large mitochondrium (17). Pig. 12 is Wilson's case in the spermatocyte of the scorpion Centrurus, where the mitochondria are in the form of a single ring which splits into four, and each spermatid cell gets one portion of the ring {27). Pig. 13 is that of the segmenting ovum (Limnaea). The Golgi rods (G) lie inert in the cytoplasm just like the mitochondria, and do not keep around the asters of the segmentation spindle {17, 24). Possibly all eggs (as well as some spermatocytes, etc.) undergo this sort of dictyo- kinesis and chondrokinesis. It is to be noticed that the process of dictyokinesis and chondro- kinesis is much less exact than that of karyokinesis. In fig. 7 the chromosomes are split longitudinally and not merely sorted oiit into two portions containing undivided elements, as occurs with the mitochondria and Golgi apparatus. These facts, which have been treated at length in other papers {17), should be borne in mind by those who would consider that the mitochondria are in * See also Murray, Zool. Jahrb., Bd. xi. Tlie Identification of Intracelhdar Structures. 101 some way bearers of " factors of heredity." It is quite evident that iu no cases at present observed do the mitochondria or Golgi elements become distributed between the daughter-cells quite like the chromosomes. Explanation of Text-figs. 8-14. Illustrating usual and unusual types of Dictyokinesis and Chondrokinesis. Letters. — Gx = Golgi rod dividing by binary fission. MR = mitochondrial ring. SB = spindle bridge. (Other letters as in text-figs. 4-7.) Fig. 8. — Late anaphase or telophase. Equatorial plate forming. Fig. 9. — Late telophase ; spindle bridge established from remains of old spindle fibres. Combination of chromosomes to form a nearly solid mass ; Golgi rods gathered around the forming archoplasmic sphere. Fig. 10. — Nucleus reformed ; appearance of karyosome and plasmosome ; re- constitution of sphere ; Golgi rods beginning to clivide (Gx). Fig. 11. — First spermatocyte of Paludina (and also exemplifies second sperma- tocyte of Centrums), showing division of large mitochondria by a constriction in the middle across equatorial plate. Fig. 12. — First spermatocyte of Centrums, showing mitochondrial ring, which later divides into two sections shaped like those in previous figure. Fig. 13. — Type of dictyokinesis, found especially in segmenting eggs (possibly all eggs), in which the Golgi elements lie inert in the cytoplasm, and are not attached to any part of amphiaster. In later stages during organogeny this type reverts to that in text-figs. 4-10. Fig. 14. — Type of dictyokinesis in many vertebrate somatic cells (e.g. thyroid), in which the Golgi apparatus breaks up into irregular granules (G), which keep around the zone of the amphiaster, but do not necessarily adhere to the astral rays. This is possibly a transition form between those in text-figs. 4-10 and 13. In text- fig. 14 the mitochondria are drawn in rings ; the ceU is the telophase of mitosis. 102 Transactions of the Society. On the Nomenclature of Cell-Division. Cell-division therefore involves at least three operations — that of the careful division of the chromosomes ; and that of the irregular sorting out of the mitochondria and of the Golgi elements into two subequal portions. The words " karyokinesis and mitosis " refer to the chromatin ; it seems advisable to use the words " cell- division," "cytokinesis " to mean all three processes, karyokinesis, dictyokinesis and chondrokinesis, as below : — [Karyokinesis and Mitosis (Chromatin) Cell-division or Cytokinesis i Dictyokinesis (Golgi apparatus) ( Chondrokinesis (Mitochondria) It has now been shown in one form at least {17), that during the development of the embryo every cell which divides not only undergoes karyokinesis but also dictyokinesis and chondrokinesis, and the latter processes are probably as universal as karyokinesis. It is important to notice that karyokinesis, dictyokinesis and chondrokinesis are all preceded by the division of the centrosome, though the latter is possibly stimulated to divide by the nucleus. To bring the process of division of the centrosome into line with the above nomenclature, it might be called " centrokinesis," from Kevrpov, and Klvr]aismium mixtures, which necessitate a stain which will " bite in.'" In every case the above- mentioned stains are best used only after constant practice. Lately certain workers (including myself) have been getting beautiful results by fixing in chrome-osmium, staining intensely in dense hasmatoxylin such as that of Benda or Heidenhain, or Mallory (>♦?), then under-differentiating, and subsequently staining in Altmann's acid fuchsin and picric acid. The latter differentiates the sections to the correct stage. I have also got remarkable results by fixing in chrome-osmium, staining in a black hfematoxylin, and counter- staining in acid fuchsin-picric acid (Van Gieson). The widely published statement that Altmann's acid fuchsin picric acid produces granules (precipitate) in cells, and that Altmann's granules are artefacts, is absolutely false. Altmann's method merely stains very efficiently bodies which can be seen in the fresh cell. Fischer's {19) critique is incorrect, and is due to his ignorance of cytology. On the Chemical Constitution of Mitochondria and GoLGi Apparatus. Both Golgi apparatus and mitochondria I believe to consist of a substratum of living protoplasm denser than the surrounding medium in which they lie. In the first place, therefore, I consider that an inquiry into the structure of these cell organs is an inquiry also into the structure of living protoplasm. Besides the basic protoplasmic part of both mitochondria and Golgi apparatus, there are other substances present associated with the basic proto- plasm. It is such associated matter which focuses our attention on these cell organs and enables us to fix and stain them specific- ally. I believe that the well-known changes in fixing and staining affinities undergone by these cell organs are caused by the varying qualities, and even absence and presence, of the associated sub- stances of mitochondrium or Golgi rod. Faure-Fremiet {^5) describes how he extracted a lipin or phosphatide from desiccated Ascaris ovaries, and has given some account of its properties. In the first place I am not satisfied that Faure-Fremiet has extracted the lipin from the mitochondria alone, for in Ascaris one gets two sorts of yolk and numerous Golgi rods, all of which might, and probably did, contribute towards Faure-Fremiet' s extract. Before the latter observer can produce evidence of a satisfactory nature he must remove his mitochondria by some method whereby contact with yolk and Golgi rods is avoided. According to Faure-Fremiet 116 Transactions of the Society. his extracted body is liardly'soluble in warm absolute alcohol or chloroform ; it is insoluble in acetone, absolute ether or mixtures of alcohol and ether ; with aq. dist. it forms an ultramicroscopic emulsion, and has no action on polarized light. Chromic acid and bichromate of potash transform the lipin into an insoluble product. Osmic acid is reduced by it very slowly, even at a temperature of 60'' C. It should not be considered that tests of which the above is a specimen apply to the cell intra vitam during the process of fixing, because Carnoy's fluid, which is a mixture of alcohol absolute, acetic acid and chloroform, will be found to sweep every- thing out of the cytoplasm of the Ascaris ovum. This of course need not vitiate the truth of Faure-Fremiet's experiments in vitro ; but it must be remembered that such in vitro experiments do not shed much light on the problems we have before us, and often do not agree with the evidence of the microscope. It seems certain that the Golgi rods contain small quantities of some fatty sub- stance which, judging from the OSO4 test (Kopsch), might be olein, but this test is very meagre evidence. By iixing a tissue lirst in formalin and subsequently treating in OSO4 (Sjovall) it is often possible to blacken the mitochondria, the formalin having the effect of assisting the reduction of the OSO4, though OsOi by itself very rarely blackens the mitochondria ; the mitochondria in the larger oocytes in the frog ovary go black in Kopsch (OSO4). While the Golgi apparatus and the mitochondria closely resemble each other in the fact that both have as their basis a substratum of protoplasm, the associated "fatty" or lipin sub- stances also in each are often very closely similar in chemical nature, though I have never found that they were quite similar. The formol or chrome fixation followed by iron-hnematoxylin as a stain seems to bring both mitochondria and Golgi rods into evidence by the fact that the formol or chrome fixes and makes stainable the protoplasmic basis. Possibly it is the albuminous part also which impregnates in Golgi or Cajal's method. On the other hand, Kopsch's method and Sjovall's method (OSO4) appear to depend on the presence of some associated " fatty " substance in either the Golgi rod or mitochondrium, and the former contains more of this " fatty " substance than the latter. In his recent monograph dealing with "Lecithin and Allied Substances " Maclean (o) says of the function of lipins, which are found in all parts of the body, " A perusal of the results of the work undertaken to elucidate the biological significance of the lipins justifies the assertion, that so far tlie special part played by the lipins in the activity of the organism is entirely unknown to us." This is a modern bio-chemist's view ; it may be unduly pessimistic, but it illustrates the fact that our knowledge of the connexion between these substances and the vital phenomena of the cell is still a blank. Possibly a more complete liaison between The Identification of Intracellular Structures. 117 workers of Maclean's type and the cytologist may produce happier results. Maclean does not mention anything of the literature on the mitochondria. General Summary. There is some considerable difficulty in distinguishing several categories of cell elements. The Golgi apparatus, mitochondria, Yolk, and fat are, or contain, substances often identical and generally chemically allied. For this reason great care must be exercised in any attempt to identify a given cell body, and it is clearly recognized that the mixture of two or more of the above-mentioned elements may lead to confusion. The characteristics of the various elements of the cell, which the zoologist meets, and the manner in which they may be distinguished, has been indicated in tabular form. It is hoped that these Tables will prove useful to embryologists and others who might wish to ascertain the nature of any enigmatic cell body under their notice. Finally, it may be pointed out that such Tables can only be made inclusive and perfectly efficient after criticism and trials by other workers, and I would welcome any suggestions of this kind. Bibliography. (For a fuller list see the papers of Pappenheiiner, Duesberg, Gatenby, and Hirschler.) 1. Mann, G. — Physiological Histology. Oxford, 2. BoLLES Lee. — The Miorotomist's Vademecum. 3. Leathes, Maclean, Plimmer, etc. — Monographs on Bio- chemistry. 4. Best. — (Glycogen Staining.) Zeit. wiss. Zool., xxiii. p. 319. 5. GoLGi, C. — Intorno alia struttina delle cellule nervose. Bol. del Soc. Med.-Chir. di Pavia (1878). Di un metodo per la facile e pronta demostrazione dell' apparato reticolare interne delle cellule nervose. Ibid (1908). 6. Hirschler, Jan. — Uber die Plasmakomponenten des weiblichen Gesch- lechtszellen. Arch. Mikr. Anat., Bd.89, Heft 1. 7. Jenkikson, J. W. — Vertebrate Embryology. Oxford, 1913. 8. KoPSCH, F. — Die Darstellung des Binnennetzes in spinalen Ganglien- zellen und anderen Korperzellen mittelst Osmiumsaure. Sitzungsber. d.k. preuss. Akad. d. Wiss. zu Berlin. 9. Meves, F. — Die Spermatocytenteilungen bei der Honigbiene. Arch. f. mikr. Anat., Bd. 70. +" 10. Pappenheimer, a. M. — The Golgi Apparatus : Personal Observations and a Review of the Literature. Anat. Eecord, ii. No. 4 (1916). 11. Granata. — I mitochondria nelle cellule seminali mgtschili di Pamphagus marmoratus. Biologica, ii. No. 4. 12. Terni Tul. — Condriosomi, idiozoma, e formazioni periidiozomiche nella spermatogenesi degli Anfibii. Arch. f. Zellforch, Bd. xii. 14. 13. Champy, Ch. — Eecherches sur I'absorption intestinale et le role des mitochondries dans I'absorption et la secretion. Arch. d'Anat. Micr,. xiii. (1911-12). 118 Transactions of the Society. 14. CowDRY, E. V. — Eelations of Mitochondria and other Cytoplasmic Con- stituents in Spinal Ganglion Cells of Pigeon. Internat. Monats. f. Anat. u. Phys. Bd. xxix. 15. DuESBERG, J. — Plastosomen. " Apparato reticolare interno " und Chro- midialapparat. Ergeb. d. Anat. u. Entwl., Bd. xx. (1911). E. Halfte. 16. Faure-Fremiet. — Etude sur les mitochondries des Protozaires et des cellules sexuelles. Arch. d'Anat. Micr., xi. ♦•l?. Gatenby, J. Bronte. — Various papers in the Quart. Journ. Micr. Sci., 1914-19. 18. Cajal, Eamon y. — Various papers, especially in later numbers of the " Trabajos del Laboratorio de Universidad de Madrid." 19. Fischer, A. — Fixirung, Farbung und Bau des Protoplasmas. Jena. 20. HiRSCHLER. — Uber Plasmastrukturen (Golgi'sche Apparat u. A.) in den Tunikaten, Spongien und Protozoenzellen. Anat. Anz., xlvii. 289. 21. Weigl. — Vergleichende-zytologische Untersuchungen iiber den Golgi- Kopsch'en Apparat u. A. Bull. Af ad. Sc. Cracovie, 417 (1912). 22. Perroncito. — Contribution k I'etude de la biologie cellulare. Le phenomene de la dictyokinese. Arch. Ital. de Biol., liv. (1910). • 23. Deinecka. — Das Netzapparat von Golgi in einigen Epilhel-u. Binde- gewebszellen. Anak Anz., xli. (1912). 24. Casteel. — Germ Cells of Argas. Journ. Morph. (1915-16). 25. Faure-Fremiet. — Le Cycle germinatif chez I'Ascaris. Arch d'Anat. Micr. XV. (1913). 26. Sjovall. — «-'ber Spinalganglienzellen und Markscheiden. Zugleich ein Versuch, die "Wirkungsweise derOsmiumsaure zu analysieren. Anat. Hefte, Bd. 30 (1906). 27. Wilson, E. B. — Distribution of the Chondriosomes to the Spermatozoa of Scorpions. Nat. Acad. Sci. Philadelphia (1914). See also (17). 28. Rio-HoRTEGA, P. Del. — Un nuevo metodo de investigacion histologica e histopatologica. Boletin Soc. Espan. Biol., No. 35 (1918). 29. Noticia de un nuevo y f acil metodo para la coloracion de la neuroglia y del tijido conjuntivo. Trab. Labor. Biol. Madrid, Tome xv. (1918). 30. Sobre la fina texturadel cartilago de los cefalopodos. Boletin Soc. Espan, Biol., No. 36 (1918). 31. Details nouveaux sur la structure de I'ovaire. Trab. Labor. Invest. Biol. Madrid, Tome xi. (1913). 110 lY. — A Metliod of Adjusting Tube Levgth. Ey H. Hartridge, M.A., M.D., F.R.M.S., Fellow of King's College, Cambs. (Read December 18, 1918.) One Diagram. Eeside the method of adjiistiDg tube length which has been completely described by Ainslie {!)* there is, I have found, another technique which has certain advantages. This may be described as follows : — With the microscope set ugjn the ordinary way, and with the condenser correctly centred, a slit-shaped aperture cut in suitable material (cardboard, sheet metal, etc.) is mounted beneath the condenser in such a way that the slit may be caused to travel at right angles to its long axis. In this way the beam of light is caused to traverse different p&rts of the condenser aperture. (See diagram.) Coiyp&N&ER MnvARLt •PlA-PMRAW Diac^ram showing position and direction of motion of slit in relationship to the ° aperture of the substage condenser. The eye-piece to be emploved is fitted with a pointer, the end of which is near the centre of the field. (For the pointer a stiff hair or bristle will be found suitable.) The eye-piece being placed in the draw tube, the edge of some conspicuous part of the specimen is brought close to the end of the pointer. * The italic figure within brackets refers to the Bibliography at end of the paper. 120 Transactions of the Society. [If subsequently it is found necessary to employ a different eye-piece, then it must either be parfocal with the one for which the tube length has been corrected or suitable readjustment of tube length effected. This may be easily carried out if, after changing the eye-pieces, the focus is restored, not by touching the iine-adjustment but by moving the draw tube. Por this purpose a rack-work draw tube is an advantage, but is not essential. Small tight-fitting rings of brass of the correct width may be used for rendering ordinary or compensated eye-pieces parfocal. This of course cannot be done in the case of holoscopic eye-pi6ces because the focal plane shifts with the adjustment of compensation.] The microscope is now focused with the pointer corresponding to some suitable part of the slide. In the case of histological or bacteriological specimens no difficulty is encountered, because almost any outstanding feature may be employed. In the case of diatoms a different procedure will be necessary, because the structure to be examined may not be resolved when the slit is placed beneath the condenser because of the small illuminating •cone. If coarse structure, such as a mid-rib or a broken edge or even dust particles, lie in the same plane as the structure to be resolved, they may be used for the purpose of tube-length adjust- ment. The image of some suitable portion of the object having been caused to correspond with the end of the eye-piece pointer, the image is carefully focused with the slit in the centre of the aperture of the condenser. The slit is now moved from side to side across the back of the condenser, and the image carefully watched. In general the image will be found to move either in the same or in the opposite direction of the slit. If in the same direction, the tube length is too short, and vice versa. If the microscope possesses a mechanical draw tube, the correct adjustment is very quickly made, for it is then found that with a good objective the image is practically stationary. In fact, in my opinion, the l)etter the objective the more definitely and rapidly can the adjustment be made. Now, in a poor objective it may be found that under no conditions will the image remain stationary ; for example, as the slit is moved from the centre outwards, the image may be found to move first against the motion of the slit, then back to its old position, and then over to the other side. This shows that (for this setting of the draw tube) there is over-correction of the ^-zone, correct correction of the ^-zone, and under-correction of the f-zone. A longer setting of the tube will give increased movement and therefore increased over-correction of the ^-zone, -over- correction in the ^-zone, and correction in the f-zone. A shorter tube corrects the ^-zone at the expense of ^ and |. It is thus impossible by adjusting tube length to eliminate the spherical aberration. Much good work can be done even with such an A Method of Adjusting Tube Length. 121 objective if the most is made of this method. For example, to resolve Pleurosigma the zones, roughly, 0'3 N.A. on either side of the central zone are used. If the central zone and these zones be adjusted to be in spherical correction, then to a certain extent the corrections of the other zones do not matter. This is the adjustment at which coarse and fine details are found to focus approximately together in tlie same plane. Most objectives show some spherical error in tlie outer zones. This may be ignored when using the method for correcting tube length, if a |-zone of illumination is to be employed, and if the object is not of such a nature that the outer zones are illuminated by diffracted or refracted light. Consideration shows that the principal advantage of this technique over other methods is that by it the different zones of the objective are separately investigated, and therefore jnore information is obtained than by previous methods in which the objective is treated as a whole. The adjustment of tube length rapidly becomes automatic in practice : " motion of image with the slit " equals " plus " equals "a longer tube"; "motion against the slit" equals "minus" equals " a shorter tube." This method is found to be of wide application, and is at present being more fully* worked out for making complete measurements of the optical performance ot objectives. The Application of the Method to the Substage condensek. This method is also found to be very useful for adjusting the distance between the illuminant and the substage condenser in order to eliminate spherical aberration. In my opinion it has advantages for this purpose over previous methods. The tech- nique may be briefly described as follows : — The same slit-shaped aperture is mounted beneath the condenser as previously described for the method of adjusting tube length. The objective to be used is now focused on the slide and the condenser adjusted so that the image of the illuminant is centred and roughly in focus. The card is placed beneath the condenser mounting so that the slit is roughly central with the optical axis. (This is readily done by slipping out the eye-piece and looking down the tube.) The con- denser is now carefully focused so that the image of the illuminant is in the same plane as the slide. The card is now shifted so that the slit travels at right angles to its long axis, and the image of the illuminant carefully watched. In general the image will be seen to move either in the same or in the opposite direction to the slit. The movement of the image of the illuminant is of course judged in reference to some prominent feature on the slide, in 122 Transactions of the Societij. order to eliminate any additional movement due to error in cor- rection of the objective. If the image of the illuminant moves in the same direction as the slit, it signifies under-correction, and a more distant light source is therefore required ; if the opposite direction, over-correction is present and the light source should be nearer. The rule is therefore the same as that found for an objec- tive : " Movement with " equals " plus " equals " a greater distance is required ; " " movement against " equals " minus " equals " nearer light source should be used." The Theory of the Method. The basis of this method of adjusting tube length may be of interest, and is therefore briefly described as follows : — In the case where the tube length has been properly adjusted spherical aberration is eliminated, and therefore rays starting from the point M'here the optic axis meets the specimen all meet at a point again on the axis. Therefore, as different objective zones are exposed the image remains stationary. If the tube length is too short, then, as is well known, the outer rays focus closer to the objective than the inner rays — that is to say, rays from the outer zones of the objective have met one another to form a focus, and have then crossed over to the opposite side before the plane of the focus for the more central rays is reached. Those from the left-hand edge of the objective aperture will therefore be found on the right, and vice versa. Now, the left-hand edge of the objective aperture is exposed when the slit beneath the condenser is to the right, and therefore when the slit is on the right the image is also on the right, and vice versa ; in other words, the image moves in the same direction as the slit. If the tube length is too long, then the central rays form a focus before the outer rays have done so. At the plane of the focus of the central rays, therefore, the outer rays have not yet met — that is, the rays from the right-hand edge of the objective aperture are still on the right, and those from the left on the left. Since, as before, the right-hand edge of the objective aperture is exposed when the slit below the condenser is to the left, the image is on the right when the slit is on the left, and vice versa, and the motion of the image is therefore in opposition to that of the slit. Relative Advantages of Different Methods. The three alternative methods are : — 1. Trial and error method. 2. Ainslie's method. 3. Author's method. 1. The trial and error method suffers from tha disadvantages A Method of Adjusting Tube Length. . 123 that the point of correct adjustment is indefinite, and the personal equation very great. 2. The method employing similarity of images above and below focus (Aiuslie's method) applies a definite criterion ; the personal equation is therefore relatively small. It can be applied in almost all cases met with in practice, and is of special value for work on Diatoms. It requires no apparatus other than a good fine- adjustment. The information given concerns the adjustment of tube length only ; little or no inference can be drawn as to the correction of the zones of the lens system of different N. A. 3. Method employing movement of image with alteration of zone (Author's method) employs a very definite test, and there- fore has the advantage of a low personal equation. It requires special apparatus ; this is however of a simple nature. It can be used for investigating the correction of the different zones of an objective or condenser, and it is this property which gives the method its principle advantage. For this purpose the Abbe test plate forms the best object. Difficulties may be encountered when the method is used on Diatoms. With ordinary slides of an histological or bacterioloojical nature this does not occur. This method has been elaborated in order to give data of the convection of different zones of microscopic objectives. Details of the technique will be described in a future paper. Eeference. 1. AiNSLiE. — Photomicro. Soc, 1R16, p. 23. 125 V, — A Standard Microscope. By LiEUT.-CoL. J. ClibboRxX, C.I.E., B.A, F.R.M.S. Eead March 19, 1919. I AM somewhat diffident of my ability to place before the Council and Fellows of this Society a proposition which appears not only appropriate but urgent at the present time — namely, to draw the attention of this Eoyal Microscopical Society to what may justly be termed both a privilege and a duty. My proposition is that this Society should at once take measures to design and specify the British Standard Microscope. It seems almost unnecessary to give reasons in support of this proposal ; the Government and the trade of this country are pressing strongly for invention, design, and standards to prevent the alien from overwhelming British manufacture, and it would be difficult to find a case in which this regrettaljle result is more likely to occur than that of the microscope, unless proper measures are taken at once. It may be suggested this duty is to the manufacturers, and not to this Society ; but a little consideration will show that the duty of the trade is to mapufacture well and economically and not to research. For the latter the trade rarely has either the methods, the funds, or the leisure, nor is there ready to hand the scientific knowledge, talent, and experience available in the Fellows of this Society, who collectively constitute the proper authority to seal the result of their deliberations as a standard for the Empire. As a matter of business detail, it need hardly be said that the selection of a particular firm in the trade as the producer of the standard would not conduce to commercial amiability, nor would a co-operative arrangement be practicable or likely to produce the result desired. It thus appears evident that this national work falls naturally to the Society, and I trust those Fellows, whose knowledge and experience in this matter we. all admire and respect, will suppoi t the suggestion, and that the Society will take the matter up with vigour, and with a determination to spare no effort to place this country ahead of all rivals in microscope efficiency and production. I have looked through many catalogues, both home and foreign, in the endeavour to trace some leading idea in the designs offered ; there may be such, but, if so, it is camouflaged to all but experts. It however appears evident that a monocular microscope stand K 126 Transactions of the Society. can be designed which will fulfil all the obligations of medical, biological, petrological, metallurgical, and chemical science, and be adapted for photo-micrographical work. That certain difficulties have to be overcome is undeniable, but none of these appears likely to be insuperable. It would be presumptuous on my part to enter into the details involved in my proposal, but perhaps I may be allowed a few suggestions derived from my experience in manufacture generally, as these may possibly conduce to economy in construction, if nothing else. That the stand be designed not as a concrete whole, but so as to- admit of successive additions of other standard parts as required. That it should be recognized that the optical parts of the microscope cannot be standardized except as regards their parts- fitting to the stand. That all fittings, other than optical, be standardized. That each part of the microscope be made of the material best suited to the strains and wear it has to undergo. That the design should aim at simplicity, a balance of the moving body in all positions, perfect rigidity, uniformity of move- ment round the arc traversed by the moving body, and artistic finish. It should not require clamping, which is likely to disturb adjustments, and must to some extent distort a delicate instrument. The manufacture should be carried out by precision tools and precision grinding to limit-gauges, so that all the parts of all instruments will be interchangeable. Kegarding rigidity and materials, it may be noted that brass, the material usually employed heretofore, has a tensile of from 12-5 to 21 tons per square inch, and elongation of from 28-65 p.c, while aluminium-bronze and rubel-bronze have tensiies of 43 tons, with only 12 '5 p.c. elongation; these bronzes appear more suitable material for the stand than brass to secure rigidity. A little book, "Metals and Alloys," published in 1918 by the Metal Industry, 33 Bedford Street, Strand, gives information regarding some 500 metals and alloys, which may be found useful. Attention may also be called to die-casting, which, though more expensive than ordinary brass-founding, produces castings in unlimited number of identical form, of a close texture, and requiring little or no machining. There are several firms in London die- casting, and if in time this method can be applied to hard material, it is certain that its introduction to microscope manufacture would conduce materially both to standardization and economy. In conclusion, I may remark that you cannot manufacture unless you have standards, but you cannot have standards unless you use precise methods and tools, and that you cannot have a really good instrument at a reasonable price unless you manufacture. 127 SUMMARY OF CURRENT RESEARCHES RELATING TO ZOOLOGY AND BOTANY (principally INVERTEBRATA and CRYPTOGAillA), MICKOSCOPY Etc.* ZOOLOGY. VERTEBRATA. a. Embryology, Evolution, Heredity, Reproduction, and Allied Subjects. Inbreeding; and Sex-Ratio in Albino Rats. — Helen Dean KiNa {Journ. Exper. Zool., 1918, 27, 1-35, 1 fig.). The normal sex-ratio in the stock experimented with was 105 males to 100 females. In inbreed- ing without selection there was in six generations little change. In inbreeding further with females from litters with an excess of males the ratio rose above the norm, except in the tenth generation. In the eleventh generation it was 145 males to 100 females. The first twenty- five generations of this series comprised 1752 litters, with 1:3,11G individuals, 7116 males and 6000 females, the total ratio being 117 males to 100 females, 12 points above the norm. In this series the- breeding females were selected from litters containing an excess of males. In a second series, where the breeding females were taken from litters containing an excess of feiqales, the deviation from the norm was in the reverse direction ; for the entire group of 794 litters the sex-ratio was 82 males to 100 females, 23 points below the norm. Through selection the inbred strain was thus separated into distinct lines, and it ' will be seen that selection had the greater influence on the female line. The experiments seem to indicate that the female has more influence in determining . the sex-ratio than has the male. " Yet it is not in the differentiation of the ova, nor in the development of the spermatozoa, that the key to the riddle of sex-determination will be found. A know- ledge of the interaction of the germ-cells, and of the conditions that influence it, must be gained before the final solution of this problem can be attained." J. A. T. * The Society does not hold itself responsible for the views of the authors of the papers abstracted. Tha object of this part of the Journal is to present a summary of the papers as actually published, and to describe and illustrate Instruments, Apparatus, etc., which are either new or have not been previously described in this country. X 2 128 SUMMAEY OF CURRENT RESEARCHES RELATING TO Inbreeding and Body Weight in Albino Rats. — Helen Dean King {Journ. Exper. Zool, 1918, 26, 1-54, 14 charts). The general course of the growth in body weight of inbred rats is similar to that of stock animals. For the first six generations there was malnutrition, and the b.ody weights were under the normal. Many had defective teeth, and the majority of the females were sterile. When nutritive conditions were improved the animals quickly regained their normal body size, and the tendency to sterility and malformation was checked. J. A. T. Inbreeding and Fertility in Albino Rats. — Helen Dean King (Journ. Exper. Zool., 1918, 26, 335-78, 2 charts). Two series of albino rats were inbred, brother and sister, for twenty-five generations. The two series combined comprise a total of 3408 litters, which contained 25,452 individuals. The inbreeding did not decrease the produc- tiveness. The constitutional vigour did not seem to be impaired. The span of life in both sexes was increased. The results obtained do not accord with the general view regarding the effects of inbreeding, since they indicate that inbreeding per se is not necessarily inimical either to fertility or to vigour. Success or failure in any series of inbreeding experiments would seem to depend on the character of the stock that is inbred, on the manner in which breeding animals are selected, and on the environmental conditions under which the animals are reared. J. A. T. Feeding Sudan to Young.Albino Rats.— S. Hatai [Journ. Exper. Zool., 1918, 26, 101-117,' 3 charts). Albino rats, 27 to 33 days old, were fed with Sudan III. mixed in olive oil. In all cases the normal rate of growth was retarded to a considerable extent. Liver and pan- creas show a steady increase in weight ; the thymus, testes and ovaries show a striking diminution. There was a high degree of antemia. The composition of the organs is more or less altered, there is an increase of water content in the blood, lungs and pancreas, while a reduction occurs in the liver, spleen, kidneys, heart and brain. In the last the reduction is small, but quite uniform, and in every specimen. J. A. T. Suckling and Rate of Embryonic Development in Mice. — W. B. > KiRKHAM {Journ. Exper. Zool., 1918, 27, 49-55). In mice simul- taneously suckling and pregnant, the removal of all but one of the suckling young at any time during the first six days after the birth of the suckling litter leads in some instances to implantation of the embryos as soon as they reach the uterus, but in other cases the implantation is more or less delayed. If the same removal takes place at any time from seven to fourteen days after the birth of the suckling litter the result is delayed implantation. The full activity of the mammary glands seems to be the chief cause of delayed implantation in the case of mice which are suckling young, but this influence is subject to marked individual variation. J. A. T. Effect of Alcohol on Guinea-pigs. — Charles R. Stock ard and George N. Papanicolaou {Journ. Exper. Zool., 1918, 26, ] 19-226, 9 tables, 9 figs.). This communication presents the results obtained ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 129 during the sixth and seventh years of an experiment on the modification of mammalian germ cells by the treatment of parental generations with alcohol. In general it may be stated that the oflFspring produced when treated males were paired with normal females were inferior in several respects as compared with other offspring from the same normal mothers bred to control males of exactly the same original stock. Further, when the male offspring from treated fathers were mated with normal females, the individuals resulting from such matings were as a group decidedly inferior to the young produced by normal females when mated with control males. This group inferiority was present not only in the grandchildren but in the next generation as well. In general terms, an experimental treatment may act upon the germ cells of an animal so as to modify them. They are changed in some way which lowers their ability to react normally in combination with germ cells from another individual. Thus zygotes are produced which tend to develop abnor- mally, grow slowly, or die during early stages. The subnormal condition may be continued through a number of generations beyond the animals directly treated. J. A. T. Amnion-Formation in a Bat.— A. Celestixo da Costa {C.R. Soc. Biol. Paris, 1919, 82, 588-90). In one of the Microcheiroptera, Miiiiopterus schreibersii, there is a hollowing out of the embryonic disc to form a closed, relatively large cavity, comparable to the primitive amniotic sac in Pteropus and other forms. At this stage the developing egg is a vesicle with a trophoblast wall, containing two other vesicles. One is hollowed out in the ectoderm of the embryonic disc. The other, much the larger, is the endodermic or umbilicar vesicle, its wall being the primary endoderm. The ectodermic cavity is quite distinct from the subsequent tropho-ectoblastic cavity. Later on the amniotic folds form the definitive amnion. J. A. T. Amnion Formation in Mammals. — A. Celestino da Costa {C.R. Soc. Biol. Paris, 1919, 82, 60-4-5). As van Beneden indicated, there is in some cases a primordial amniotic cavity formed within the em- bryonic disc, preceding the tropho-ectoblastic space, just as that precedes the definitive cavity delimited by the amniotic folds. This is seen in Jliniopteriis, Rhinolophus, Sus, and some other types. But in some other cases — e.g. hedgehog, mole, rabbit, carnivores — the primordial amniotic cavity is rudimentary or absent, and the amnion is formed- from folds. Or, thirdly, the amnion may be formed by excavation of the embryonic disc and histological differentiation of the walls of the primordial cavity, which persists. This is seen in Primates, GaUopithecus, Pteropus, guinea-pig, and some other forms. J. A. T. Effect of Cytolysins on Embryos. — M. F. Guyer and E. A. Smith {Journ. Exper. ZooL, 1918, 26, 65-82). Lens tissue of rabbits and mice injected into fowls excites the production of specific anti-bodies. If the serum, sensitized by the presence of these, be injected into pregnant rabbits, the anti-bodies may attack the lenses of the unborn young. The reaction is not invariable, however, since a majority of even all of the individuals of a litter may not be acted upon, or a given 130 SUMMARY OF CURRENT RESEARCHES RELATING TO individual embryo may be aifected in only one eye. This is difficult to explain. The liquefactions that occur indicate a true cytolytic effect. Of the several proteins composing the lens, one is fibrous, and it is upon this that the sensitized serum seems to operate. No effect was observed in the mother, which may be due to the meagre circulation in the adult lens. The fact of chief interest is that visible specific structural modifica- tions can be engendered in the young in utero by means of specifically sensitized serum, J. A. T. Female Reproductive System in some Falcons.— Max Kollman {Bull. Soc. Zool. France, 1919, 44, 43-52, 3 figs.). In six cases (four of Accifpiter nisiis, and one of Astur palumbarius and Tinnunculus tmmmculus) paired ovaries were found ; and two persistent Wolffian ducts were found in two cases. A duck observed by Chappellier had two ovaries and two oviducts, and someti^nes laid two eggs in a day. In the cases described by Kollman the right oviduct remained vestigial, which is puzzling. In most birds a ventral sagittal partition divides the abdominal cavity into two distinct compartments. J. A. T. Hybrids Between Fundulus and Mackerel. — H. H. Newsman (Journ. Exper. ZooV, 1918, 26, 391-421, 4 figs.). Crosses have been effected between Fundulus heieroclitus 9 and Scomber scomhriis $ . The former has red chromatophores and the latter green ones ; the former has solid black chromatophores and the latter delicately branched ones. In proportion as the paternal element (indicated by the mackerel chromatophores) vigorously finds expression, in like proportion is development retarded and various types of monster appear. The most successful embryos are, in so far as the chromatophores are concerned, pure maternal. The great majority of the hybrids are subnormal, especially in their apical structures (eyes, hearts, etc.), and at the same time show obvious paternal inheritance. A somewhat smaller group of hybrid embryos show large apical parts and reduced basal parts ; such embryos are usually pure maternal as to chromatophores, or at least in the region of differentiation. Such anomalies are to be interpreted as diffei'ential recovery products. The capacity of apical structures for recovery is greater than that in basal structures. Thus there may be heads differentiated without bodies, or with at best rudimentary bodies, and occasionally isolated eyes and hearts. It seems, then, that in heterogenic crosses no harmonious structural differentiation can result unless there be neutralization or elimination of the disharmonious parental (in this case paternal) materials. If the latter function actively in the development, there can result only retarded and sub- normal embryos and larv», and the vast majority of the hybrids in this case were of this type. J. A. T. b. Histology. Epithelial Movement in Tissue Culture.— Shinichi Matsumoto {Journ. Exper. Zool., 1918, 26, 545-64, 9 figs.). Corneal epithelium of the adult frog, cultivated in plasma, shows various types of amoeboid movement, accordinor to the nature of the substratum. As a rule the ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 131 cells have a strong tendency to cling to their own kind, and thus extend in sheets, although under certain conditions active amoeboid movement of isolated cells is also to be seen. In the majority of cultures move- ment into the medium or along the endothelial surface (or both) takes place according to the consistency of the culture medium. When serum is used no migration of the culture into the medium takes place. Experi- ments exclude chemotactic influences from the living tissue ; there may be vigorous cell-movement on glass and celloidin films. Stereotropism plays an important role in cell-movement. The behaviour of corneal epithelium in vitro serves to throw some light on epithelial growth in vivo,' for the experiments show cleai'ly that the epithelium is able to extend fi'om the cut end quite rapidly in sheets into the medium (plasma), or on the tissue (plasma and serum), and can cover a large area without mitotic cell-divisions being necessary at all. J. A. T. Cell Movements in Corneal Epithelium.— Shinichi Matsumoto {Jouni. Exper. Zool., 11)18, 27, 37-47, 4 figs.). Though the cornea of the adult frog is thin and transparent enough for the observation of epithelial movement, it is not an easy matter to note the details of the process. But if the epithelium of the cornea be vitally stained with neutral-red and Nile-blue characteristic granules are. seen in the cyto- plasm. These exist through the entire period of cell activity, without practically affecting the cells, and facilitate the study of cell movements. Phagocytic phenomena of the corneal epithelium in reference to melanin and carmin were definitely demonstrated. J. A. T. Minute Structure of Monkey's Pharynx.— Isaac Boetnowsky {Ann. Sci. Nat. {Zool), 1919, 2, 175-98, 10 figs.). This is a study in histology and specificity. A description is given of the epithelium of the rhino-pharynx, the bucco-pharynx, the laryngo-pharynx, the larynx, and the laryngeal sac in Cercopithems, and of the glands in the first four of these regions, and of the associated adenolymphoid tissue. It. is shown that the minute structure of the various regions in Cercopitheciis nictitans differs from that in man, Theropithectis gelada, and chimpanzee. J. A. T. Structure and Origin of Dentary Enamel. — Ed. Retterer {G. R. Soc. Biol. Paris, 1919, 82, 571-4). There is sometimes an enamel organ, e.g. in armadillo, which. does not produce enamel, but the histo- genesis shows that enamel never appears without being preceded by ivory. The prisms of enamel arise not from epithelial cells, but from a transformation of the peripheral ends of the rodlets of ivory. The pre- dental organ of epithelial nature is a sine qua non of the formation of a tooth. For although the epithelial cells do not furnish any part of the tooth, they lend to the mesodermic cells which they cover and define a •developmental capacity which they would not otherwise have. They form an environment in which the mesoderm cells become odontoblasts, and these odontoblasts produce both ivory and enamel. J. A. T. Cortex of Roots of Teeth.— Ed. Retterer {C. R. Soc. Biol. Paris, 1919, 82, 618-21). The root of the tooth has layers of ivory or den- 132 SUMMARY OF CURRENT RESEARCHES RELATING TO tine identical in structure and development with those of the crown. The root is likewise surrounded by a layer of bony tissue, whicli develops like that of the maxilla at the expense of inter-dento-maxillary connective tissue. Thus arises the osseous cortex (" cement " of some authorities), while the rest of the inter-dento-maxillary tissue uniting the cement to the maxilla persists in a fibrous or ligamentar state. J. A. T. Melanophores of Horned Toad. — Alfred G. Redfield (Journ, Exper. ZooL, 1918, 26, 275-338, 5 pis., 8 figs.). In Phrynosomci cornutum light produces an expansion, its absence a contraction of the melanophore pigment. High temperatures produce contraction and low temperatures expansion. The heat effect dominates at extremes of tem- perature, the light effect at mean temperatures. Light coming from a dark substratum produces an expansion, from a light substratum a contraction of the pigment. Mild mechanical stimuli do not affect the melanophores ; mild faradic stimuli cause contraction of the pigment, and so do noxious stimuli, such as violent mechanical or faradic stimuli. The melanophores, or some closely associated tissues, are receptors of photic and thermal stimuli. There are no specific receptors for noxious stimuli. The eyes are receptors for stimuli which cause adaptive re- actions of the melanophores. The melanophore pigment is contracted by the direct action of nerves as well as by the direct action of adrenin. The spinal cord contains, between the eighth and thirteenth vertebrae, nervous structures through which pass the impulses which cause the contraction of the melanophore pigment. Impulses pass from this part of the cord directly to the adrenal glands. Impulses also pass from this part of the cord posteriorly, and perhaps anteriorly, within the cord to segmentally arranged peripheral nerves which connect directly with the melanophores. The peripheral fibres are a part of the sympathetic division of the auto- nomdc nervous system. The reactions of the melanophores of the horned toad produce a series of colour changes correlated with tlie rhythm of day and night, an adaptation of the colour of the skin to that of the environment, and a characteristic pale condition of the skin during nervous excitement. The daily rhythm of colour change is caused by the direct action of photic and thermal stimuli upon the melanophores or some closely associated tissue. The adaptive reactions of the melanophores depend upon stimuli received through the eyes. The contraction of the melanophore pig- ment during nervous excitement is brought about by the co-operation of nervous impulses delivered to the pigment cells by the sympathetic nervous system and the secretion of adrenin by the adrenal glands. There is a marked resemblance between the innervation of melanophores and the innervation of smooth muscle. J. A. T. Division of Melanophores of Trout. — P. Murisier {Bull. Soc. Vaudoise, 1919, 52, 97-8). In Trutta lacustris the melanophores are all mononuclear until a few days before hatching. The transition from the mononuclear to the binuclear phase is accomplished by a typical ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 133 taryokinesis, but the two daughter-cells remain together in the region corresponding to the equator of the division-spindle. The mitosis appears to occur very rapidly, for it is difficult to catch many cells in the process. ' J. A. T. c. Greneral. Aqueous Humour. — ^y. A. Osborne {Journ. Physiol., 1919, 52, 317-50.) The aqueous humour presents the singular phenomenon of a body fluid surrounded by living tissue, and yet containing so little protein that it may be regarded as practically protein-free. The chief solids in it are metallic salts. But the common statement that the aqueous humour has a higher osmotic pressure than the blood is challenged. In fact, it is found that the osmotic pressure of ox aqueous humour is equal to that of blood. Other quantitative considerations support the view that the humour is a blood filtrate. The osmotic pressure of the blood proteins in the iridic vessels will cause absorption of aqueous humour if the excess pressure in these vessels is less than 30 mm. Hg. J. A. T. Moult and Regeneration of Pelage in Deer-mice. — H. H. Collinj? {Journ. Exper. Zool., 1918, 27, 73-99, 2 pis.). In Peromyscus the moulting is, in a measure, comparable in regularity of sequence and directions of growth to the moults of birds. In the post-juvenal moult, growth occurs more or less independently on certain regions of the body, suggesting the mode of moult in the feather tracts of birds. In adults the moults are generally more irregular and inconspicuous. By plucking out juvenal hair, the precocious appearance of the post-juvenal pelage may be induced, and this is sometimes preceded by the out-growth of an' aberrant type of hair, with abnormal pigmentation, which persists only for a short time. The normal sequence of the incoming hair is profoundly modified by artificially induced regeneration. Restoration of pelage in adults occurs irrespective of the season, after the plucking out or clipping of the old hair. This restoration is accomplished by the outgrowth of new hairs, except in the case of the vibrissa, which are replaced by the elongation of the cut hairs. Restoration is much more rapid when the hairs are plucked out than when merely cut. Light appears to be a negligible factor in the development of the differential coloration of the dorsal and ventral surfaces. J. A. T. New Mendelian Variety of Norway Rat. — P. W. Whiting and Helen Dean King {Journ. Exper. Zool, 1918, 26, 55-04). A new Mendelian variety, known as ruby-eyed dilute grey, has been found near the Zoological Laboratory of the University of Pennsylvania. The hair is Ught sepia at the tip and grades to white at the base. The eye- colour is ruby. The new variation is recessive to intense pigmentation. Ruby-eyed dilution is allelomorphic with albinism. The F^ individuals, called fawns, are intermediate both in hair and in eye-colour. Fawns when bred together i")roduced eighty ruby-eyed dilutes, one hundred and fifty-six fawns, and eighty albinos. Ruby-eyed dilutes crossed witli red-eyed yellow rats produce rats of the wild type. J. A. T. 134 SUMMAKY OF CUEKENT RESEARCHES RELATING TO Changes in Life-conditions in Illinois River. — S. A. Forbes and E. E. Richardson {Bull. Nat. Hist. Survey, Illinois, 1919, 13, 139- 56). A study of the changes in the plankton and fishes in the Illinois River since the increase of Chicago sewage emptied into the stream and the reclamation of parts of the overflow regions. " A river and its plankton are a flowing soil and its crop, both slipping away continuously, but both renewed constantly from an exhanstless source of supply. The fertility of the flowing water at any time is not dependent on the fertility of that which has preceded it, but on materials of fertility brought into it from the watershed .... The plankton productivity of the stream does not depend primarily on the richness and extent of its own flowing waters, but on those of its subsidiary breeding grounds, and if these are not adequate to the maintenance of a plankton sufficient to consume all the readily available food materials of the stream, more or less fertility of the current waters must go to waste." The yield of fishes in the Illinois River has been diminishing for many years in the face of a greatly increased and rapidly growing supply of the raw materials of their food, because of the narrowing, of the backwaters, which are for the river important places of digestion and assimilation in which the organic wastes of the city and of the land are worked up into forms fit for food for .the higher animals. It is not only space but time that has been seriously reduced. J. A. T. Monthly Occurrence of Pelagic Eggs in Port Erin Bay in 1918. — A. Scott {Lancashire Sea-Fisheries Laboratory Report, 1919, 27, 15- 24). It was found that pelagic eggs were present in the plankton for nine months out of the twelve. The increase at the beginning of the year was very rapid, rising from 0*83 per haul of the coarse net in January to 106 '4 in March — the maximum. A reduction set in during April, which was continued to June. A well-defined increase took place in July, which was largely due to the presence of the eggs of two Species of fish (rockling and topknot). After that the pelagic ■eggs ceased to be conspicuous among the plankton organisms, and finally disappeared in September. J. A. T. Intensive Study of Isle of Man Plankton. — W. A. Herdman, A. Scott, and H. M. Lewis {Lancashire Sea- Fisheries Laboratory Report, 191^, 27, 25-35). " One conclusion that is becoming clear from our accumulated observations of the last ten years is the surprisingly small number of different kinds of organisms — both plants and animals — that make up the bulk of the plankton that is of real importance in relation to fish. Our food from the sea seems to depend, in great measure, ultimately upon comparatively few species of Diatoms and Oopepoda respectively. A very large proportion of the Diatoms in the spring plankton and of Copepoda in that of late summer belong in ■each case to a very few different kinds, so that one can select about half- a-dozen species of Copepoda which constitute by far the greater part of the summer zooplankton, and about the same number of Diatoms which similarly make up the bulk of the spring phytoplankton year after year. These few species, belonging to these two very widely ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 135 separated groups, thus come to be the most significant organisms in relation to the annual metabolic cycle of our seas and the food supply from our coastal fisheries." The most significant Copepods are — Olthona similis, Pseudocalanus elongafus, Acartia claim, Temora longicornis, Paracalamis parvus and Calanus finmarchicus. Their distribution is not uniform, and variations in the distribution must have a marked effect on the presence and abundance of at least such migratory plankton- eating fish as herring and mackerel. J. A. T. Respiration in Fishes, — A. KroctH and Isabella Leitch {Journ. Physiol.,. 11>19, 52, 288-300). Fish blood appears to be subtly adapted to the available supply of oxygen, that of carp, eel and pike, which are occasioually exposed to low oxygen pressure, being different (in dissocia- tion curves) from that of cod, plaice and trout, which normally are never exposed to very low oxygen pressures. The adaptation of the fish blood must be brought about by some substance or substances present along with the htemoglobin within the corpuscles, and the general significance of the haemoglobin being present in semi-permeable corpuscles, and not simply dissolved in the plasma, is ascribed to the fact that the arrangement makes possible the adaptation of the hemo- globin to extremely different respiratory conditions without interfering with the general composition of the blood. A ha3moglobin dissolved in blood plasm can, in- a cold-blooded animal, only be useful at very low oxygen pressure, and that is probably why in Invertebrates the posses- sion of hsemoglobin is restricted to forms which are habitually exposed to such pressures. J. A. T. I f INVERTEBRATA. ^%l . Mollusca. Muscle-flbres of Molluscs. — R. Anthony {Arch. Zool. Exper. Notes et Revue, 1919, 58, 1-10, 3 figs.). In the adductor muscles of bivalves there are two kinds of fibres : (a) smooth and slowly contracting (the nacreous portion) ; and {h) rapidly contracting and striated, or with lozenge-shaped marking. Those with • the lozenge-shaped marking are intermediate between smooth and striped. In Anomia the same fibre may show both kinds of marking. The transition from smooth muscle to that with lozenge-shaped marking is adaptive to certain functional requirements which the author expounds. J. A. T. • y. Gastropoda. Dimorphic Spermatozoa in Paludina vivipara. — J. Bront6 Oatenby {Quart. Journ. 3Iicr.Sci., 1919, 63, 401-43, 2 pis., 21 figs.). In the case of these dimorphic spermatozoa, the atypic (giant) cells have numerous fine granular mitochondria, while the typic have a very small number of large, stout, rod-shaped mitochondria. In the typic divisions it seemed that in some cases the large rods were merely sorted out into two groups to the daughter-cells, while in other cases the rods were divided in the middle. In the atypic divisions the mitochondria acted 136 SUMMARY OF CURRENT RESEARCHES RELATING TO like those of Helix aspersa or other Pulmonates. In rare cases the mitochondria of the typic spermatocytes are very large, coarse granules, quite distinct from the smaller granules of the atypic series. The author discusses the " Nebenkern " or " Golgi " apparatus. J. A. T. G-eiminal Nurse-cells of Testacella. — J. Bro>s^te Gatenby (Quart. Journ. Micr. Sci., I'Jll), 63, 401—13, 2 pis., 21 figs.). In this slug some of the germinal epithelial cells, instead of forming ova, spermatozoa, and follicle-cells, become much enlarged to form yolk-cells or nurse- cells, which have very large hyper-chromatic nuclei and a cytoplasm full of yolk-discs. They nourish the ova and sperm-cells in spring and summer ; they degenerate in part towards autumn and winter ; there is a re-activation of some of them in the early spring, but degeneration again occurs in many cases. The number of chromosomes in Testacella seems to be something over twenty, and the haploid number over ten, probably about twelve. The giant germ-cells seem to contain an irregular and over-numerous series of chromatin loops. J. A. T. Gametogenesis and Early Development of Limnsea stagnalis. — J. BEONTf: Gatenby {Quart. Journ. Micr. Sci., 1919, 63, 445-91, 2 pis., 6 figs.). In the oogenesis of this water-snail the germinal epithelial cells show an excentric " Golgi apparatus " or " Nebenkern," consisting of a number of rods (chondrioplasts or dictyosomes). In the progerminative oocyte mitochrondria appear very early in the zone of the Golgi apparatus. The Golgi rods divide by binary fission, and keep increasing in number, each becoming provided with a small portion of the included archoplasm. The apparatus spreads through the whole ovum-cytoplasm. The mitochondria grow, divide, and spread uniformly. The individual Golgi rodlet never grows beyond a certain size. The first yolk-discs make their appearance after the Golgi elements and mitochondria have spread far through the growing oocyte. Towards the end of oogenesis the oocyte gradually becomes filled with fluid vacuoles. In the spermatogenesis no mitochondria were discovered. In spermateleosis (the metamorphosis of spermatid into spermatozoon) there is a mito- chondrial residue sloughed off. The tail of the sperm appears as a new formation of mitochondrial matter around the axial filament. The Golgi apparatus is sloughed off during spermateleosis. The nuclear head is very small compared with the long mitochondrial tail. In segmentation the mitochondria are equally divided ; so is the Golgi apparatus ; both persist in organogeny. J. A. T. Arthropoda. a. Insecta. Germ-band in Holly Tortrix Moth.— L. H. Huie {Proc. R. Sue, Edinburgh, 1918, 38, 154-65, 2 pis.). The development of Eudemis nsevana can be followed in the living egg with unusual clearness. Beneath the inner pellicle is a finely and densely granular protoplasm, and inside this is the yolk-plasm. Maturation takes place about the time of oviposition ; the first polar body divides again. The first division of ths zygote occurs two or three hours after oviposition ; in a few hours ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 137 there are sixteen nuclei, which spread throughout the yolk ; after a few more nuclear divisions the resulting amoeboid cells tend to the peri- plasm ; there a blastoderm is established, the periplasm being broken into a chain of cell-like territories, each with a iiucleus in its centre. The cells of the blastoderm and those in the yolk now show a large nucleolus. The completion of the blastoderm is achieved when the cells become sufficiently numerous to form a continuous epithelium. A pjortion of this is differentiated to form the ventral plate or germ- rudiment, consisting of columnar epithelium. The amnion fold arises at its margins. There is an inward movement of the germ-rudiment into the yolk, which becomes broken up by vitellophags. There is a remark- able turning movement of the germ-rudiment, which becomes crescentic in outline. The germ-rudiment assumes the form of a germ-band, with cells still more columnar and closely apposed, with two procephalic lobes at the head-end, with a narrow median groove which sinks in to form the •"inner layer," which soon becomes segmented. J. A. T. Pupae of Sphingidae. — Edxa Mosher (Ann. Entomol. Soc. America, 1918, 11, 403-42, 1 pi.). It is shown that pupal characters indicate natural relationships and confirm those indicated by adult characters. The majority of the sphinx moths spend their pupal life in a cell in the ground, v^hich is formed by the mature larva ; the body-surface is generally punctate, with indeterminate transverse striations between the punctures, and the sides of the abdomen in the spiracular region are usually more strongly sculptured than the rest of the body ; the cephalic margins of abdominal segments 5-7 ai-e strongly furrowed or carinate in most cases; the furrows (called " spiracular") may be sometimes so deep as to form a sort of pocket-like cavity ; no setse have been observed on the body ; the length of the maxillae in the pupee often greatly exceeds the length of the wings, in some instances being twice their length, and there are three different ways of providing for this extra length. The spiracular furrows and the maxillae afford the best characters for classifying the pupte, and a key to the genera is submitted. J. A. T. South African Bagworms. — C. B. Haedenberg (Annals Natal Museum, 1919, 4, 143-227, 1 pi., 25 figs.). In -continuation of previous studies the author gives a detailed account of twelve species, taking account not only of structure, but of life-history and economic import- ance. The species belong to the genera Acanthopsyche, Clania, Manatha, Semimanatha, and Monda ; and many minute details are given as to the setae and mouth-parts of the larvai. There' is much interesting informa- tion in regard to the structure of the bags and the habits of the larvae. J. A. T. Pulsatile Tergal Organ in Lepidoptera. — Frank Brocher (Arch. Zool. Exper., 1919, 58, 149-71, 8 figs.). In Sphinx convolvuli there is a mesotergal pulsatile organ like that in water-beetles. It is in a sense the true heart, being much more important than the dorsal blood-vessel in driving the blood. Its importance makes it easier to understand the prolonged survival of insects which have lost their abdomen or have 138 SUMMARY OF CURRENT RESEARCHES RELATING TO been badly wounded in the abdomen. There is a sort of thoracic cycle. In the convolvuhis moth there is also a small metatergal pulsatile organ, which receives alary veins. But no connexion with aorta or dorsal blood-vessel c'buld be seen. In Dyticidse it is this metatergal pulsatile organ that is of the greater importance. J. A. T. Intestinal Epithelium of Silkworm, — A. FoA {Boll, Lah. Zool. Agric. Fortici, 1918, 12, 217-44). The mid-gut epithelium shows cylindrical and calyciform cells, differing in structure and function. Both are secretory, but the cylindrical cells are likewise absorbent. In diseased (flaccid) silkworms the calyciform cells are reduced or modified. J. A. T. Male Genital Tube in Coleoptera. — Frederick Muir (Tratis. Entomol. Soc. London, 1918, 22, 3-9, 1 pi.). This organ arises as a tube in a median position from the connecting membrane between the ninth and tenth sternites. There is no evidence whatever to indicate that it is composed of amalgamated paired organs (called parameres by some authors) ; the terminal lobes, cap-piece and tegminal strut are secondary outgrowths from the tegminal fold. There is no indication that any abdominal segment or sternite is incorporated into the tube. The organ is a tubular evagination and no more. J. A. T. Spiracles of Some Muscid LarvsB. — John L. Froggatt {Proc. Linn. Soc N.S. Wales, 1918, 43, 658-67, 1 pL). An account is given of the minute structure of the spiracles of four species of CalUphora, Lucilia sericata, and Ophyra nigra. This has a practical interest, for it is found that from the posterior spiracles in particular it is possible to identify the different species, even when they are rotten. The spiracles are probably very important in connexion with the destruction of the maggots of these species by poison, for apart from the mouth and anus they are the only openings. In these species there are no pores in the cuticle as there often are in insect larvae. But the important point zoologically is the specificity of the spiracular apparatus. J. A. T. Bot-Flies. — S. Hadwen and A. E. Cameron {Bull. Entomol. Research, 1918, 9, 91-106, 1 pi., 10 figs.). Careful descriptions and admirable figures are given of three species of Gastrophilus occurring in Canada — G. intestinalis, G. nasalis, and G. hsemorrhoidalis. They differ in the mode of attachment of the egg to the hair, in the external features of the newly hatched larvae, and in the appearance and habits of the adults. The eggs ot'G. intestinalis do not readily hatch unaided, but apparently require the application of moisture and friction or shock. A large number of the eggs of G. nasalis hatched spontaneously, and so did a few of those of G. Iiseniorrhoidalis. This supports the view that the larvEe of these two species may penetrate directly into the integument of the host. The lesions on the skin of the intermaxilloxy space and the lips observed at the time the eggs were hatching may be due to direct penetration of the larvas of G. nasalis and G. hsemorrhoidalis respectively. The newly emerged larvae of G. intestinalis failed to penetrate the hair- bearing skin of the horse, but positive results were obtained when they ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 139 were placed on portions of the buccal mucosa of a horse and calf recently killed. A larger number succeeded in penetrating the papillated portion of the calf's tongue, as compared with the non-papillated. Of the three species, G. intesUnalis causes the horses less apprehension than the others. The provision of leather flaps on the lips of the horse, cut into strips comb-wise, is advocated as likely to give good results in warding off the attacks of G. hsemorrhoidalis. J. A. T. Effect of a Diet of Ductless Glands on Development of Flesh-flies. — B. W. KuNKEL {Journ. Exper. Zool, 1919, 26, 255-64). Feeding larvae of Lucilia and other flesh-flies upon mammalian thyroid and nothing- Qlse tends to retard slightly the growth of the larvie, and consequently to reduce the size of the resulting pupae. But a diet of thymus tends to increase their size. Thyroid feeding tends to hasten the onset, and to shorten the period of pupation, J. A. T. Development of Maggots in Sterilized Tissue. — E. Wollman {G.R. Soc. Biol. Paris, 1919, 82, 59?.-4). It has been shown that the larvae of blow-flies {Galliphoravomitoria) are able to develop satisfactorily in flesh sterilized at a temperature of 115", but that the results are not so good when the sterilization is effected at higher temperatures. This has been attributed to the destruction of vitamines. To eliminate disadvan- tages due to hardening of the tissue, Wollman took fragments of brain and sterilized them in tubes at 130° for forty-five minutes. Eggs of the blow-fly sterilized in sublimate were placed in the tubes, and it was found that the larvse developed much better than they did in the flesh sterilized at 115°. On the fifth day they were quite normal. It may be that the vitamines are not destroyed, it may be that the larvte possess " accessory factors of growth," it may be that the larvse produce vita- mines in the substratum, but further experiments are needed. J.A.T. Note on Nutritive Value of Sterilized Food. — Chaeles Richet {G. R. Soc. Biol. Paris, 1919, 82, 601-2). In reference to Wollraan's experiment, Richet points out that no general statement can be made in regard to the destruction of vitamines by heat. Dogs fed exclusively on flesh cooked at 100° die in four to five weeks, but dogs fed on a mixture of bread and flesh sterilized for three-quarters of an hour at 135° may thrive. J. A. T. Light Reactions of May-fly Nymphs.— W, C. Allee and E. R. Stein, jun. {Journ. Exper. Zool., 1918, 26, 423-58, 4 charts). The light reactions of the positively phototactic May-fly nymph, Epeorus; were reversed by treatmerit with alcohol, lowered temperature, calcium chloride, and other influences. Nymphs so reversed had a lower rate of metabolism, as measured by resistance to potassium cyanide, than have normal nymphs. The negatively phototactic nymph, Leptophlebia, was similarly reversed, with accompanying stimulation or depression of metabolism, as measured by resistance to the cyanide. A negatively phototactic nymph belonging to the Heptageninaj was reversed in its light reactions, with accompanying increase or decrease in carbon dioxide production as measured by Tashiro's biometer. The phototactic reaction 140 SUMMAKY OF CURRENT RESEARCHES RELATING TO is correlated with the metabolic condition. The experiments indicate, but do not prove, that certain changes in metabolism cause the reversals in reaction to light. All nymphs that reversed their light reactions were either stimulated or depressed, but stimulation or depression does not necessarily involve phototactic reversal. J. A. T. Life-history of Red-currant Aphis. — Maud D. Haviland {Proc. R. Soc. Edinburgh, 1919, 39, 78-112,9 figs.). This Aphis, J/v/ms ribis, is dimorphic in respect of certain features of the antenna and of abdominal and wing dimensions. The nature of the food, whether healthy or blistered by the attack of the fundatrix, seems to be the determining factor of this dimorphism. The form from healthy leaves is probably identical with M. tchitei Theobald and J/, dupar Patch. The insect is migratory; and in summer colonizes certain Labiatae and other weeds ; but this migration is not obligatory, and the entire life- cycle may be passed on currant. On its summer host this species has been described as Fhorodon galeopsidis Kaltenbach. There is a decline in fertility in the later part of the summer among the forms remaining on currant. This is caused by a lower birth-rate, and not by the shorten- ing of the life of the parent. This decline, together with the attacks of predaceous and parasitic enemies, accounts for the frequent disappearance of the species from the currant in August and September. Both sexual forms may be produced, and eggs may be laid on either host-plant. Males transferred from Labiate to currant can fertilize females on the latter. . J. A. T. Wings and Tracheas of Termites.— Claude Fuller {Annals Natal Museum, 1919, 4, 19-102, 9 pis.). The ribs supporting the termite wing are derived from thickenings of the cellular tissue of the de- veloping organ. One of these thickenings is in the form of an ambient, and develops independently around the margin, whilst the rest form about tracheae. Subsequently, that portion of the ambient thicken- • ing which extends along the outer margin is converted into the rib costa. The trachege of the wing-sac develop from two or from three buds, forming very early in nymphal life upon each of the four sections ot the spiracular trunk tracheae within the meso- and metathorax, and not upon the dorsal and ventral longitudinal trunks, as described in other cases. The position and branching of the longitudinal ribs of the wing are almost wholly dependent upon the position and development of the Jongitudinal tracheae, except in the case of the costa, which is not preceded by a trachea. The specialization of the wing-ribs by reduction follows the reduction of the tracheae. A newly-hatched termite shows a framework of comparatively few simple trachea?, from which a multitude of dichotomizing, arborescent, and other trachea? gradually develop and grow. The specialization of the respiratory system is by reduction. The valvular spiracles of the abdomen of the adult are derived by gradual transformation from the occluding apparatus of the spiracles with a fixed opening exhibited by the nymphs. The slit-like spiracles of the abdomen of highly-distended queens in Termes and Odontotermes re- present disruptions of the final valvular spiracles. J. A. T. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 141 Chromatin Maturation in Spermatogenesis of Locusta viri- dissima.— Otto L. Mohe (Arch. Biol, 1919, 29, 579-752, 5 pis,, 9 figs.). There is in the spermatogenesis a multiplication-period, in which the primitive sperm-cells give rise to primary spermatogonia, and these to secondary spermatogonia. Then there is a maturation-period, with two maturation-divisions in the two generations of spermatocytes. There is a monosome (or genuine unpaired chromosome) which is divided longitudinally in all the divisions except the first maturation- division, where it passes undivided into one of the daughter-cells. This is an indication of the fact that the first maturation-division is a reducing division. It is probable that an ovum (with 14 + 1 chromo- somes) fertilized by a spermatozoon (with 14 ordinary chromosomes and a monosome) will develop into a female, while one fertilized by a sperma- tozoon without a monosome will develop into a male. J. A. T. Insect Life of New Zealand Mountain Station. — F. W. Hilgendorf {Trans. New Zealand Inst., 1918, 50, 135-44), Two important factors in the environment are dead sheep and white flowers, for these are correlated with the two most striking features of the insect life — namely, blowflies by day and moths by night. Apart from birds the only native land vertebrate is the common lizard {Lygosojna moco), but fish in the lakes and streams are numerous. The introduction of trout must have made an enormous difference to the insect and probably to the bird population of the district. Hudson has shown that the stomachs of sixty trout taken from various localities contained 4804 Neuroptera, 662 other insects, and twenty-eight other animals. An account is given of the insects of various associations — the tussock grass- land, the lake and swamps, the river-bed, the shrub-land, the forest, and the rocks. The short paper contains many interesting notes. There is the diving dragon-fly, Somatochlora smithii, which picks gnat-larvre from the surface of the water, immersing its head ten or twenty times in a minute. When the blowflies do not find a dead sheep they are urgently impelled to any place where there is the faintest scent of animal matter. " I have seen Calliphora quadrimaculata so violently impelled to lay her eggs somewhere' that she has done so on a bicycle-tyre where it had just been pressed with a perspiring hand." J. A. T. Mutation in Coccidse. — K. Kunhi Kannan {Trans. Entom. Sac. London, 1918, 130-48, 4 pis.). In Coccns viridis Green collected in Mysore when the pest first appeared there in 1912 there were seven segments in the antennae. But specimens collected in 1913 and after- wards, though undoubtedly C. viridis in other respects, showed in the antemiEe a reduction to three segments by the coalescence of the terminal five into one. In Java, besides the typical C. viridis, there are two dis- tinct types, with very variable but usually eight antennal segments, highly unstable and with a host of intermediate forms. The author brings forward evidence to show that Pidvinaria psidii, also very variable in size, antennas, and anal plates, is a mutating species from which C. viridis and its variants have been derived directly or indirectly. J. A. T. 142 SUMMARY OF CURRENT RESEARCHES RELATING TO As regards Mutation in Coccidse. — E. Ernest Green {Trans. Entomol. Soc. London, 1918, 149-54). That a reduction in the number of antennal joints has been observed in South Indian specimens of Lecaniwn {Coccus) viride and Fulvinaria psidii does not necessarily form an argument in favour of the transmutation of the two species, but suggests, rather, that a similar environment has induced in the two a tendency to variation in the same direction. Green holds that the genera Pidvmaria and Lecanium, though very closely allied, have quite well-defined boundaries. He sees no more justification for regarding L. viride and its allies as having been directly derived from P. psidii than for assuming a similar, relationship between L. hesperidum and P. Jloccifera, or many other pairs that might be mentioned. J. A. T. Study of Cockroach Head. — E. Bugnion {MT. Schwek. Entom. Ges., 1916, 12, 383-400, 1 pi., 4 figs.). An account is given of the structure "'' 6 5 4 3 2 7 ^-.. N^ Sagittal Section op thb Head of Blatta americmia x 9. (The mandibles and first maxillae have been removed.) Tongue. 2. Labrum. 3. Entrance to pharynx. 4. End of labro- pharyngeal sinus. 5. Frontal ganglion, 6. Antennary nerve. 7. Section of optic nerve. 8. Sub-cesophageal ganglion. 9. Anterior sub-intestinal ganglion. 10. Posterior sub-intestinal ganglion. 11. Recurrent nerve. 12. Duct of salivary glands. 13. Duct of salivary reservoirs. 14. (Esophagus. 15. Prothoracic ganglion. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 143 of the head and its appendages in Blatta americana and B. australasise. There is no large new fact to report, but the description is exceedingly careful and the figures are good. A structure hke the quadrilateral tentorium inside the head is minutely described, and the mouth-region (including tongue, hypopharynx, pharynx, as well as appendages), is particularly well described. J. A. T. ;3. Myriopoda. Vulvae of Diplopoda. — Henry W. Brolemann and Jean L. LiCHTENSTEiN.(-'ircA. Zool. Exper., 1919, 58, 173-218, 31 figs.). A detailed account is given of the integumentary differentiation around the genital apertures of the females (when these do not lie on the second pair of appendages, but behind these), which may be spoken of as the vulva. The forms especially dealt with are Polydesmus coriaceus^ Sohizo- phyllum sabulos'Utn, and Archispirostreptus tumuUporus sudanicus. What has been called a gland is an apodermatous groove. There appear to be associated sensory set^e. "With the groove or gutter minute glands are associated, and the secretion may assist in the receiving of the sperms. But there is nothing appendicular about the vulva. J. A. T. 8. Arachnida. Water-mites from Peru and Brazil. — C. Walter {Revue Suisse Zool, 1919, 27, 19-59, 45 figs.). This contribution to our knowledge of the Hydracarina of a region that has been very slightly studied includes descriptions of twelve new species of various genera {Limnesia, Ventral surface, Neocalonijx godeti g. el sp.n., male. Frontipoda, Hygrolates, Arrhenurus, Eylais, Kcenikea and Halacarus). An account is given of Neocalonyx godeti g. et sp. n., which is related to Calonyx. J. A. T. Cavernicolous Spiders. — Louis Fage {Arch. Zool. Exper., 1919, 58, 55-148, 7 pis., 48 figs.). An account is given of the cavernicolous genus Troglohyphantes, and of its many species. They are very small spiders, 2-4 mm. in length. Some of the species, but a minority, show special features correlated with their life in caves — the de -pigmentation of the chitin, the elongation of limbs and sensitive seta?, the reduction of eyes (even to complete anophthalmia). Many species show no special features that can be correlated with cave life. Most move slowly ; they L 2 144 SUMMARY OF CURRENT RESEARCHES RELATING TO do not "feign death" ; the web is slight ; the oviposition has not been observed. The genus is separated from related forms mainly by the structure of the copulatory organs, and the evolution of this in the various species, starting from the most primitive Cantabrian and Pyren- nean forms, seems to have progressed from west to east. J. A. T. e. Crustacea. Structure of Barnacles. — Hjalmar Brooh (A^ Nor she Videnslcab. Selskahs Skrifter., 1918, 1, 1-28, 5 pis., 5 figs.). An account is given of some anatomical and histological features of Anelasma squalicola (Loven) Darwin and Scalpellum stromii M. Sars. It is shown that Anelasma, in the general structure of its alimentary canal, occupies a somewhat intermediate position between the less specialized Scalpellum and the more highly specialized Gonclioderma and Lepas. In their general structure the digestive glands of Anelasma are more highly developed than in Scalpellum, and approach the high organization of Gonclioderma ; on the other hand, their finer structure suggests resting or even degenerating tissues. The digestive intestine seems to have ceased to be a food-absorbing organ. This is associated with the development of secondary nutritive organs, the offshoots or filaments of the peduncle. These filaments have a dissolving influence on the tissue of the shark on which the barnacle is fixed, and they are abetted in this by secretions from the cement glands, which are numerous and large. They do not, as in other stalked cirripeds, combine into two groups or pass their secretion to the base of the stalk by two main ducts. In Anelasma the single gland-cells communicate by short ducts with the lacunae of the connective tissue. J. A. T. New Isopod of Natal. — Walter E. Collinge (Annals Natal Museum, 1919, 4, 229-33, 1 pi.). A peculiar and interesting form, Akermania spinosa g. et sp. U;, probably one of the Cubaridse, is described. It differs from any terrestrial Isopod hitherto described, in the shape of the cephalon, the folded coxopodite beneath the pleural plates of the first mesosomatic segment, the feeble walking legs on segments 2-7, the short expanded uropods with characteristic sette, and the shape of the telson. It shows a strong development of spines, setae, and scales. J.A.T. Development of Testes in Parasitic Copepod. — M. CAULLERYand F. Mesnil {G.R. Soc. Biol. Paris, 1919, 82, 596-8). In Xenococloma brumpti, parasitic on Folycirrus arenivorus CaulL, there is hermaphrodi- tism and apparently autogamy. In Cymothoidse, Cryptoniscidae, and similar groups there is a normal and single primordium which produces spermatozoa and ova successively or simultaneously. In Xenocmloma no germinal cells are to be seen in the embryo or in the nauplius. In the early parasitic stages, however, the ovary is distinctly differentiated and the primordium of oviducts. Connected with this primordium there is an epithelial complex, not different from ordinary epithelium, which subsequently gives origin to testes, seminal vesicle, and the so-called atrial cavity. Spermatogonia quite similar to oogonia appear in situ, in ZOOLOGY AND BOTANY, MICROSCOPi", ETC. 145 entire independence of the ovary. It may be, however, that testes and seminal vesicle arise from a transformation of what is the receptaculnm in ordinary female Copepods. Does epithelial tissue become in part germinative, or does somatic tissue become testicular ? Further inquiry is needed. J. A. T. Yolk-formation in Copepod Ovum. — H. Leighton Kesteven {Proc. Linn. Soc, N.S.W., 1918, 43, 136-41, 1 pi.). In Ubius hiUi Kestv., an endoparasitic Copepod from Ptychodera australiensis Hill, K ^^ nn^pni^ Ubms hilli Kestv. Stage in formation of new nucleus. K, karyosomes ; Nu.", the new nucleus nearly formed ; Nzi. memh.', the nuclear membrane of the old nucleus ; Nu. memh.", the nuclear membrane of the new nucleus. M' file o.^\o_ ,0 .'b „ .^ <, .% ? « / !»^o '''At'"' ' 'A Sections of mature primary oocytes, with nucleus and yolk-granules. 146 SUMMARY OF CURRENT RESEARCHES RELATHSTG TO the yolk-granules are formed by the combination of a cytoplasmic con- stituent with chromatin. The first yolk-granules appear within the nucleus. A new nucleus is formed by a pseudo-contraction of the over- laden old nucleus. This pseudo-contraction leads to the shedding of some of the karyosomes, which function as yolk-nuclei. These yolk- nuclei are stores of chromatin which continue the functional activity of the nucleus of the growing primary oocyte. That is to say, their use is to supply chromatin for that combination which results in yolk-forma- tion. The ultimate oogonium is nourished by endosmosis, the primary oocyte by the epithelium of the oviduct. In both cases the all- important substance received is the cytoplasmic constituent, which enters into yolk-formation. Chromatin constituents, however, must be derived from without in the earliest stages. J- A. T. Annulata. Polychseta of Northern Coasts of Spain. — Enrique Rioja {Tra- lajos Mus. Nac. Gienc. Nat. Madrid, Ser. Zool, 1918, 37, 1-99, 20 figs.). The 'author's report deals with eighty-one species of littoral Polychasta, including ffyalinacia fauveli sp. n. and Nereis (Nean- ihioides) boUvari sp. n. The latter is placed in a new sub-genus, including those species of Nereis in which all the groups of paragnaths are com- plete, those of the ventral basal portion of the proboscis being united in a complete girdle. In the sub-genus Neanthes the groups of jjaragnaths are also all complete, but those of the dorsal basal portion are distinctly separate from one another and from those of the ventral portion. A new variety of Glycera convoliita is based on a minute feature, the hooked end of the aciculum of the ventral blade of the parapodia, which are also more robust than in the type. J. A. T. Intercalary Growth in a Maldanian Worm. — P. Fauvel {Bull. Soc. Zool. France, 1919, 44, 3G-40). In a strange Polychtete, Gra- vierella multianmdata g. et sp. n., there is a remarkable proliferation. The succession of segments in the abdominal region is interrupted by the intercalation of a series of segments, the first few very rudimentary, the others gradually increasing until the normal size is exhibited. This was observed in a dozen cases. It recalls the proliferation in a tape- worm and the stolonization of some Syllids. In one case there were two proliferating zones widely separated. It may be a rapid method of making good posterior breakages, or it may be the result of some unknown irritation. J. A. T. Anabiosis in Earthworms. — Peter Schmidt {Journ. Exper. Zool.^ 1918, 27, 57-72). Earthworms subjected to exsiccation or desiccation pass into a state regarded as analogous to the anabiosis of Tardigrada, Rotifers, and Nematodes. They lose their mobility ; they shrink to one- half or one-third of their length and volume ; they show no manifesta- tions of life. No contractions were seen in the dorsal blood-vessel. The capacity for revivification may be retained for thirty-nine hours in summer, for forty-eight hours, and perhaps more, at low temperature. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 147 The limits may be due to the fact that drying of the skin is apt to destroy the capillaries and cause effusion of blood, and to tlie presence of micro- organisms in the gut and on the surface. The experiments bring out an important fact, that a large percent; ige of water can be lost with- out the complete loss of vitality. Earthworms can revive and' regain the normal state of life after a loss of 61 "6 p.c. of the weight of the body, or nearly 73 p.c. of the weight of the water contained in the body. This makes it easier to understand, or, perhaps one should say, jto believe, that small creatures like Tardigrades, Rotifers, and Nematodes can revive after losing 80-85 p.c. of the water in their bodies. J. A. T. Oligochsets of the High Alps. — Emile Piguet {Rev. Suisse. Zool., 1919, 27, 1-17). Collections from the mountains of Scandinavia and Switzerland are compared, and the species common to both countries are noted. The Naididse are represented by Paranais uncinata, Chseto- gaster diaphaniis, and Stylaria lacustris ; the Tubificidte by two species of Tuhifex ; the Enchytrseidae by a number of doubtful forms ; the Lumbriculidje by Lumhriculus variegatus and StyUdrilus heringianus ; and the Lumbricidas by Lumdriciis melibseus. J. A. T. Nematohelminthes. New Nematode in Calves. — A. L. Sheathee (BuU. Agric. Research, Inst. Pusa, 1919, 86, 1-5, 5 pis.). A parasite is described which causes parasitic gastritis in calves. The caudal bursa is trilobed, with the posterior lobe symmetrically placed ; there are very long and slender spicules ; the vulva is close to the posterior end of the body. These features distinguish the worm from the genera Htemonchus, Nemato- dirus, Trichostrongylus, Ostertagia and Cooperia known to occur in the stomach proper and duodenum of calves. J. A. T. Platyh.elniinth.es. Remarkable Case of Echinococcus in Lemur. — H. Blanc {Bull. Soc. Vaudoise Set. Nat., 1919, 52, 451-6, 1 pi., 3 figs.). A specimen of Lemur catta showed an almost complete invasion of the thoracic and abdominal cavities by an extraordinary number of hydatid vesicles of Echinococcus polymorphus. There was no hint of scolices developing into hydatid cysts, as might ensue if a hydatic vesicle was burst, liberat- ing the heads. It seems more likely that the lemur, which lived in a menagerie with a dog as companion, was the victim of multiple infection from the eggs of the tapeworm stage living in the dog's intestine. J. A. T. Methods of Reproduction in Cestodes. — T. Southwell and Baini Prashad {Journ. Parasitology, 1918, 4, 122-9, 12 figs.). The authors discuss the various methods of asexual and parthenogenetic reproduction amongst the Cestodes — (1) internal proliferation from the wall of the cysticercoid, as seen in Polycercus, Cocnurus, and others ; (2) endogenous 148 SUMMARY OF CURRENT RESEARCHES RELATING TO budding, as seen in Willey's Merocercus ; (3) external budding, as ex- emplified in the species of Polycerciis and Staphylocystis, described by Haswell and Hill ; and (4) parthenogenetic reproduction, uniquely illustrated in IJishia partfmiogenetica Southwell and Prashad, an adult tapeworm of doubtful affinities. J. A. T. Rhabdites of Turbellaria. — Marcel Prenant- {^Arcli. Zool. Exper., 1919, 58, 219-50, 1 pL, 12 figs.). These bodies are formed of one or more protein substances (with sulphur and phosphorus) combined with calcium. They are almost certainly nucleoproteins, arising from the degeneration of the nuclei, and may be either excretory or reserve pro- ducts. Their formation is preceded, in many cases at least, by nuclear buds and degeneration. In the epidermis of Polyclads their formation from degenerate nuclei is direct ; they have the value of nuclei ; their individualization is due to amitosis or to budding. In the epidermis of Triclads and Ehabdocoelids the rhabdites arise in superficial corpuscles, probably the basal corpuscles, and their appearance is associated with the degeneration of adjacent nuclei. In Fecampia erythrocephala, about the time of encystation and of oviposition, there is an abundant pro- duction of rhabdites, followed by their disappearance. There is probably in most cases an actual waxing and waning of rhabdites. In Prosthiostomum siphunculus there are rhabdites in the parenchyma, the third case among Polyclads. J. A. T. Reactions of Proboscis of Planaria albissima. — W. A. Kepner and Arnold Rich {Journ. Exper. Zool., 1918, 26, 83-100, 10 figs.). A proboscis severed from its adjacent ganglion still shows some reaction by disturbed movements within the sheath. In most cases a proboscis, thus separated from the central nervous system, underwent auto- amputation while lying within the sheath. Sometimes this did not happen without a disturbance of the thigmotatic conditions within the sheath. In all cases, however, the disturbance of the thigmotactic conditions of the sheath so excites the proboscis that, without the inhibitory control of the adjacent ganglia of the central nervous system, the proboscis suffers auto-amputation, and acts as an independent reflex " organism." It can carry out the three co-ordinated muscular move- ments involved in food-ingestion, provided that its entire musculature is intact. It cannot distinguish between food and non-food, for that requires the functioning of the central nervous system. J. A. T. Incertae Sedis. Transverse Fission in Phoronopsis. — J. D. F. Gilchrist {Quart. Journ. Micr. Sci., 1919, 63, 493-507, 1 pi.). This Phoronid has been observed to reproduce asexually by transverse division of the body. The division occurs in the muscular region, and the detached part is capable of locomotion. It divides a second time below the lophophore, which is thrown off and disintegrates. The remaining part, after moving about freely, develops an anterior projection (epistome ?), a lophophoral ridge, ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 149 and later an aboral projection. The epidermis of this projection is thrown into a number of involutions, by the unfolding of which it somewhat suddenly increases in length at later stages, and assumes the form of a peduncle, which fixes the animal by a mucous secretion. The whole process, from the first division to the pedunculate fixed form, occupied fourteen days. The peduncle consists externally of a prolifera- tion of the epidermis of the body and internally of modified cells of the coelomic epithelium, fatty particles and muscular elements. J. A. T. Rotatoria. Sex Determination in Hydatina. — A. Feanklin Shull {Joiirn, Exper. Zool, 1918, 26, 521-44). "When water is saturated with an atmosphere containing 60 p.c. of oxygen there is increased male- production. The same is true, Shull and Ladoff have shown, with a 40 p.c. oxygen atmosphere. The lower concentration may, perhaps, be a little more effective in inducing male-productien. Cultures in which Euglena is used as food show increased male-production ; this is partly, but not wholly, due to the oxygen liberated by the Euglena. But Euglena as food is two or three times as effective as oxygen. Manure-scum used as food is a male-repressing agent, J. A. T. Echinoderma. "Egg Secretion in Echinoderms. — Avalyn E. Woodwaed (Joiirn. Exper. Zool., 1918, 26, 459-501, 2 charts, 3 figs.). In confirmation of the work of Lillie and Glaser, it was found that the eggs of Asterias and Arhacia secrete into the supernatant sea-water a substance which causes the sperm of the same species to be activated, aggregated, reversibly agglutinated, and paralysed. The secretion is also a parthenogenetic agent. Further study showed that the presence of the secretion is necessary for the fertilization of the Qgg, for (1) immature eggs, which cannot be fertilized, produce a secretion with less than one-sixtieth the agglutina- ting power of that produced by the same eggs when mature ; (2) eggs from which the secretion has been washed do not develop when insemi- nated, but if secretion be added before insemination they develop ; (3) eggs of Arhacia which are " resistant " to fertilization late in the season also produce little secretion, but fertilize normally if secretion is added. That the secretion has a dual nature is shown by the following facts : — {a) it reacts with both the sperm and the ^^g ; {h) boiling destroys its value as a parthenogenetic agent, but not as an agglutinin ; (c) peri- visceral fluid of the same species inhibits autoparthenogenesis, but not agglutination. The secretion is probably colloidal ; it contains carbon and nitrogen, but gives no clear response to protein tests ; there is indication of the presence of tyrosine, phenylalanine, or tryptophane. Two substances can be precipitated from the same secretion — a sperm agglutinin and a par- thenogenetic agent. The agglutinin resembles an enzyme in the effect upon it of X-radiatiou. The parthenogenetic agent dissolves a fat 150 SUMMARY OF CURRENT RESEARCHES RELATING TO obtained from the eggs, and may contain a lipase. Hence it is provi- sionally called a lipolysin. " It seems probable that the factors tending to produce development in the resting egg are of the nature of enzymes. The action of these, Jobling found, may be inhibited by unsaturated fatty acids. The egg remains in the resting stage so long as the action of these enzymes is inhibited by the unsaturated fatty acid. The egg itself, when mature and in a suitable medium, produces a lipolysin which binds this inhibitor. The efficiency of the inhibitor may also be reduced by physical and chemical means. In some groups, the spermatozoon appears to bind the inhibitor, in others to increase the activity of the enzymes." J. A. T. Rhythmic Pulsation in Madreporic Vesicle of Young Ophiuroids. — James F. Gemmill (Quart. Journ. Micr. Sci., 1919, 63, 537-40, 1 fig.). In young Ophiuroids, probably OpMoglypha alUda, at the stage of a flattened disc with five blunt arms each with five tentacles, there is a rhythmically pulsating madreporic thin-walled cavity entirely com- parable to the madreporic vesicle of an Asterias larva. The pulsations are extremely regular, occurring once in every eleven or twelve seconds. It looks as if the essential part of the pulsation were the emptying and filling of spongy tissue to one side of the vesicle. The author goes on to discuss the axial organ (which he cannot regard as primarily a genital stolon), and to compare the haemal systems of Enteropneusts and Echinoderms. " J. A. T. Bottom Material Ingested by Holothurians. — W. J. Crozier (Journ. Exper. ZooL, 1919, 26, 379-89, 2 charts). It has been found possible to obtain a fairly accurate idea of the rate of feeding in Stichopus mcehii Semper, and of the maximal contents of the gut in individuals of different sizes. In certain typical areas 6 to 7 kilos (dry weight) per square metre seem to pass through the intestine of the Holothurians frequenting the spot. It is estimated that in the en- closed "sink" of Harrington Sound the amount of bottom deposit annu- ally eaten by Stichopus is perhaps 500 to 1000 tons. The fluid stomach contents are sufficiently acid to dissolve some calcium carbonate. The* mutual attraction of particles in the intestine is probably of small significance for the formation of finely-divided particles. J. A. T. • Coelentera. Significance of Calyx in Alcyonacea. — Arvid R, Molander (ArTciv Zoologi, 1918, 11, No. 22, 1-12). The term calyx has been used loosely or ambiguously in reference to various types of Alcyonarians. According to the author, it should mean (in Alcyonacea) the well- defined basal region of the free or anthocodial portion of the polyp. Into such a calyx the upper portion of the poljp can be usually re- tracted, or it may also be that on the retraction of the upper portion into the coenenchyma the calyx closes over it. The armature of the calyx agrees in the main with that of the stolons, the basal membranes, or the cortex of the colony. The spicules form eight longitudinal bands, and are in the main longitudinally disposed. According to Molander there ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 151 iS a calyx iu all genera of AlcyouidaB and Siplionogorgidfe. There is a calyx in Clavularia and in Gersemia, and probably in Tehsto and Scleran- ■thelia. Bnt the calyx occnrs in every degree of development, down to a hardly visible ring at the base of the anthocodia. It must be noted that Molander's conception of the calyx is different from that usually held. J. A. T. Membranous Forms of Colonies in Gorgonacea. — Arvid R. MOLANDER {Arkiv Zoolocji, 11, Xo. 21, 1-19, 6 figs.). It sometimes happens that a normally erect Alcyonarian forms a puzzling membranous expansion. Thus, as Broch has shown, Anthothela grandiflora may form a spreading membrane and show no trace of axis. Molander maintains that Anthelia loreaUs and A.fallax are not Clavularids but Gorgonids. It is probable that they are two varieties of Anthothela grandiflora. In the same way — a rather upsetting way — Molander regards Rhisoxenia alba as a membranous form of Gersemia fruticosa. These are very interesting and important conclusions ; we venture to suggest the need for proceeding cautiously with re-interpretations of this sort. J. A. T. Irish Actiniaria. — T. A. Stephenson (Proc. Roy. Irish Acad., 1918, 34, Section B, No. 7, 106-64, 7 pis.). An account is given, with much detail as to minute structure, of certain sea-anemones collected off Ireland by the Irish Fisheries Department. Among the notable forms is Carlgrenia desiderata g. et sp. n., which is of much systematic interest ; Cymhactis gossei sp. n., a rather curious species ; Actinernus aurelia sp. n., externally like a jellyfish, with enlarged bilobed oral disc and extreme reduction of the base ; two new species of Chondroadis,^ with tough cartilaginous body-wall ; and the variable Actinauge ricliardi Marion. J. A. T. Discussion of Leptogorgia irramosa (Grieg). — Aevid R. Molandek {Arlciv Zoologi, 1918, 12, No. 5, 1-7, 2 figs.). A fresh diagnosis is given of Leptogorgia irramosa (Grieg), an Alcyonarian that has borne various names, such as Gorgonia pinnata Ratke and Pterogorgia pinnata Grieg. There is little in the way of main stem ; the branching is irregular ; the polyps are irregularly disposed or alternate ; there is usually a distinct verruca ; the coenenchyma contains long spindles and double stars ; the polyp-lDody contains long spindles forming eight longitudinal double rows towards the base of the tentacles ; the spicules are usually red or grey-white. J. A. T. Study of Renilla.— G. H. Parker (Journ. Exp. Zool, 1919, 27, 499-507, 1 fig.). In the interesting Pennatulid, Renilla amethystina Verrill, the autozooids exhibit spontaneous withdrawal and expansion with striking independence. The rhythmic contractions of the peduncle are mainly concerned in distending the colony as a whole. As Wilson showed, an enlarged siphonozooid serves as exhalant orifice, the other siphonozooids serving for entrance. The former communicates with the " superior canal" of the rachis and the peduncle ; the " inferior canal " extends from the base of the peduncle to the rachis, where it com- municates with the autozooids. The two systems of canals communi- cate with one another at the basal end of the peduncle, and there alone. 152 SUMMARY OF QUERENT RESEARCHES RELATING TO The autozooids, though very independent, are unified in a measure ini their actions by the single organ for inflation, the rhythmically con- tracting peduncle, which thus serves the colony as a whole. In relation to the colony the peduncle is a " super-organ." The colony exhibits phosphorescence at night, but not merely by being taken during the day into darkness. The phosphorescence is localized in almost microscopic granulations on the surface of the rachis ; it may be excited from any point by mechanical or faradic stimulation ; there must be a nerve- net which controls and unifies the colonial luminosity. J. A. T. Pigment of Hydroids. — Ernest Warren {Annals Natal Museum,. 1919, 4, 103-35, 1 pi., 11 figs.). Many colonies of South Afr